Monocotyledon

Monocotyledons (), commonly referred to as monocots, (Lilianae "sensu" Chase & Reveal) are grass and grass-like flowering plants (angiosperms), the seeds of which typically contain only one embryonic leaf, or cotyledon. They constitute one of the major groups into which the flowering plants have traditionally been divided, the rest of the flowering plants having two cotyledons and therefore classified as dicotyledons, or dicots.
Monocotyledons have almost always been recognized as a group, but with various taxonomic ranks and under several different names. The APG III system of 2009 recognises a clade called "monocots" but does not assign it to a taxonomic rank.
The monocotyledons include about 60,000 species. The largest family in this group (and in the flowering plants as a whole) by number of species are the orchids (family Orchidaceae), with more than 20,000 species. About half as many species belong to the true grasses (Poaceae), which are economically the most important family of monocotyledons. Often mistaken for grasses, sedges are also monocots.
In agriculture the majority of the biomass produced comes from monocotyledons. These include not only major grains (rice, wheat, maize, etc.), but also forage grasses, sugar cane, and the bamboos. Other economically important monocotyledon crops include various palms (Arecaceae), bananas and plantains (Musaceae), gingers and their relatives, turmeric and cardamom (Zingiberaceae), asparagus (Asparagaceae), pineapple (Bromeliaceae), sedges (Cyperaceae) and rushes (Juncaceae), and leeks, onion and garlic (Amaryllidaceae). Many houseplants are monocotyledon epiphytes. Additionally most of the horticultural bulbs, plants cultivated for their blooms, such as lilies, daffodils, irises, amaryllis, cannas, bluebells and tulips, are monocotyledons.
Description.
General.
The monocots or monocotyledons have, as the name implies, a single (mono-) cotyledon, or embryonic leaf, in their seeds. Historically, this feature was used to contrast the monocots with the dicotyledons or dicots which typically have two cotyledons; however modern research has shown that the dicots are not a natural group, and the term can only be used to indicate all angiosperms that are not monocots and is used in that respect here. From a diagnostic point of view the number of cotyledons is neither a particularly useful characteristic (as they are only present for a very short period in a plant's life), nor is it completely reliable. The single cotyledon is only one of a number of modifications of the body plan of the ancestral monocotyledons, whose adaptive advantages are poorly understood, but may have been related to adaption to aquatic habitats, prior to radiation to terrestrial habitats. Nevertheless, monocots are sufficiently distinctive that there has rarely been disagreement as to membership of this group, despite considerable diversity in terms of external morphology. However, morphological features that reliably characterise major clades are rare.
Thus monocots are distinguishable from other angiosperms both in terms of their uniformity and diversity. On the one hand the organisation of the shoots, leaf structure and floral configuration are more uniform than in the remaining angiosperms, yet within these constraints a wealth of diversity exists, indicating a high degree of evolutionary success. Monocot diversity includes perennial geophytes such as ornamental flowers including orchids (Asparagales); tulips and lilies (Liliales); rosette and succulent epiphytes (Asparagales); mycoheterotrophs (Liliales, Dioscoreales, Pandanales), all in the lilioid monocots; major cereal grains (maize, rice, barley, rye, oats, millet, sorghum and wheat) in the grass family; and forage grasses (Poales) as well as woody tree-like palm trees (Arecales), bamboo, reeds and bromeliads (Poales), bananas and ginger (Zingiberales) in the commelinid monocots, as well as both emergent (Poales, Acorales) and aroids, as well as floating or submerged aquatic plants such as seagrass (Alismatales).
Vegetative.
The most important distinction is their growth pattern, lacking a lateral meristem (cambium) that allows for continual growth in diameter with height (secondary growth), and therefore this characteristic is a basic limitation in shoot construction. Although largely herbaceous, some arboraceous monocots reach great height, length and mass. The latter include agaves, palms, pandans, and bamboos. This creates challenges in water transport that monocots deal with in various ways. Some, such as species of "Yucca", develop anomalous secondary growth, while palm trees utilise an anomalous primary growth form described as establishment growth ("see" Vascular system). The axis undergoes primary thickening, that progresses from internode to internode, resulting in a typical inverted conical shape of the basal primary axis ("see" Tillich, Figure 1). The limited conductivity also contributes to limited branching of the stems. Despite these limitations a wide variety of adaptive growth forms has resulted (Tillich, Figure 2) from epiphytic orchids (Asparagales) and bromeliads (Poales) to submarine Alismatales (including the reduced Lemnoideae) and mycotrophic Burmanniaceae (Dioscreales) and Triuridaceae (Pandanales). Other forms of adaptation include the climbing vines of Araceae (Alismatales) which use negative phototropism (skototropism) to locate host trees ("i.e." the darkest area), while some palms such as "Calamus manan" (Arecales) produce the longest shoots in the plant kingdom, up to 185 m long. Other monocots, particularly Poales, have adopted a therophyte life form.
Leaves.
The cotyledon, the primordial Angiosperm leaf consists of a proximal leaf base or hypophyll and a distal hyperphyll. In monocots the hypophyll tends to be the dominant part in contrast to other angiosperms. From these, considerable diversity arises. Mature monocot leaves are generally narrow and linear, forming a sheathing around the stem at its base, although there are many exceptions. Leaf venation is of the striate type, mainly arcuate-striate or longitudinally striate (parallel), less often palmate-striate or pinnate-striate with the leaf veins emerging at the leaf base and then running together at the apices. There is usually only one leaf per node because the leaf base encompasses more than half the circumference. The evolution of this monocot characteristic has been attributed to developmental differences in early zonal differentiation rather than meristem activity (leaf base theory).
Roots and underground organs.
The lack of cambium in the primary root limits its ability to grow sufficiently to maintain the plant. This necessitates early development of roots derived from the shoot (adventitious roots). In addition to roots, monocots develop runners and rhizomes, which are creeping shoots. Runners serve vegetative propagation, have elongated internodes, run on or just below the surface of the soil and in most case bear scale leaves. Rhizomes frequently have an additional storage function and rhizome producing plants are considered geophytes (Tillich, Figure 11). Other geophytes develop bulbs, a short axial body bearing leaves whose bases store food. Additional outer non-storage leaves may form a protective function (Tillich, Figure 12). Other storage organs may be tubers or corms, swollen axes. Tubers may form at the end of underground runners and persist. Corms are short lived vertical shoots with terminal inflorescences and shrivel once flowering has occurred. However, intermediate forms may occur such as in "Crocosmia" (Asparagales). Some monocots may also produce shoots that grow directly down into the soil, these are geophilous shoots (Tillich, Figure 11) that help overcome the limited trunk stability of large woody monocots.
Reproductive.
In nearly all cases the perigone consists of two alternating trimerous whorls of tepals, being homochlamydeous, without differentiation between calyx and corolla. In zoophilous (pollinated by animals) taxa, both whorls are corolline (petal-like). Anthesis (the period of flower opening) is usually fugacious (short lived). Some of the more persistent perigones demonstrate thermonastic opening and closing (responsive to changes in temperature). About two thirds of monocots are zoophilous, predominantly by insects. These plants need to advertise to pollinators and do so by way of phaneranthous (showy) flowers. Such optical signalling is usually a function of the tepal whorls but may also be provided by semaphylls (other structures such as filaments, staminodes or stylodia which have become modified to attract pollinators). However, some monocot plants may have aphananthous (inconspicuous) flowers and still be pollinated by animals. In these the plants rely either on chemical attraction or other structures such as coloured bracts fulfill the role of optical attraction. In some phaneranthous plants such structures may reinforce floral structures. The production of fragrances for olfactory signalling are common in monocots. The perigone also functions as a landing platform for pollinating insects.
The embryo consists of a single cotyledon, usually with two vascular bundles.
Comparison with dicots.
The traditionally listed differences between monocots and dicots are as follows. This is a broad sketch only, not invariably applicable, as there are a number of exceptions. The differences indicated are more true for monocots versus eudicots.
A number of these differences are not unique to the monocots, and, while still useful, no one single feature will infallibly identify a plant as a monocot. For example, trimerous flowers and monosulcate pollen are also found in magnoliids, and exclusively adventitious roots are found in some of the Piperaceae. Similarly, at least one of these traits, parallel leaf veins, is far from universal among the monocots. Broad leaves and reticulate leaf veins, features typical of dicots, are found in a wide variety of monocot families: for example, "Trillium", "Smilax" (greenbriar), "Pogonia" (an orchid), and the Dioscoreales (yams). "Potamogeton" and "Paris quadrifolia" (herb-paris) are examples of monocots with tetramerous flowers. Other plants exhibit a mixture of characteristics. Nymphaeaceae (water lilies) have reticulate veins, a single cotyledon, adventitious roots, and a monocot-like vascular bundle. These examples reflect their shared ancestry. Nevertheless, this list of traits is generally valid, especially when contrasting monocots with eudicots, rather than non-monocot flowering plants in general.
Apomorphies.
Monocot apomorphies (characteristics derived during radiation rather than inherited from an ancestral form) include herbaceous habit, leaves with parallel venation and sheathed base, an embryo with a single cotyledon, an atactostele, numerous adventitious roots, sympodial growth, and trimerous (3 parts per whorl) flowers that are pentacyclic (5 whorled) with 3 sepals, 3 petals, 2 whorls of 3 stamens each, and 3 carpels. In contrast, monosulcate pollen is considered an ancestral trait, probably plesiomorphic.
Synapomorphies.
The distinctive features of the monocots have contributed to the relative taxonomic stability of the group. Douglas E. Soltis and others identify thirteen synapomorphies (shared characteristics that unite monophyletic groups of taxa);
Vascular system.
Monocots have a distinctive arrangement of vascular tissue known as an atactostele in which the vascular tissue is scattered rather than arranged in concentric rings. Collenchyma is absent in monocot stems, roots and leaves. Many monocots are herbaceous and do not have the ability to increase the width of a stem (secondary growth) via the same kind of vascular cambium found in non-monocot woody plants. However, some monocots do have secondary growth; because this does not arise from a single vascular cambium producing xylem inwards and phloem outwards, it is termed "anomalous secondary growth". Examples of large monocots which either exhibit secondary growth, or can reach large sizes without it, are palms (Arecaceae), screwpines (Pandanaceae), bananas (Musaceae), "Yucca", "Aloe", "Dracaena", and "Cordyline".
Taxonomy.
The monocots form one of five major lineages of mesangiosperms (core angiosperms), which in themselves form 99.95% of all angiosperms. The monocots and the eudicots, are the largest and most diversified angiosperm radiations accounting for 22.8% and 74.2% of all angiosperm species respectively.
Of these, the grass family (Poaceae) is the most economically important, which together with the orchids Orchidaceae account for half of the species diversity, accounting for 34% and 17% of all monocots respectively and are among the largest families of angiosperms. They are also among the dominant members of many plant communities.
Early history.
Pre-Linnean.
The monocots are one of the major divisions of the flowering plants or angiosperms. They have been recognized as a natural group since the sixteenth century when Lobelius (1571), searching for a characteristic to group plants by, decided on leaf form and their venation. He observed that the majority had broad leaves with net-like venation, but a smaller group were grass-like plants with long straight parallel veins. In doing so he distinguished between the dicotyledons, and the latter (grass-like) monocotyledon group, although he had no formal names for the two groups.
Formal description dates from John Ray's studies of seed structure in the 17th century. Ray, who is often considered the first botanical systematist, observed the dichotomy of cotyledon structure in his examination of seeds. He reported his findings in a paper read to the Royal Society on 17 December 1674, entitled "A Discourse on the Seeds of Plants".
 Since this paper appeared a year before the publication of Malpighi's "Anatome Plantarum" (1675–1679), Ray has the priority. At the time, Ray did not fully realise the importance of his discovery but progressively developed this over successive publications. And since these were in Latin, "seed leaves" became "folia seminalia" and then "cotyledon", following Malpighi. Malpighi and Ray were familiar with each other's work, and Malpighi in describing the same structures had introduced the term cotyledon, which Ray adopted in his subsequent writing.
 In this experiment, Malpighi also showed that the cotyledons were critical to the development of the plant, proof that Ray required for his theory. In his "Methodus plantarum nova" Ray also developed and justified the "natural" or pre-evolutionary approach to classification, based on characteristics selected "a posteriori" in order to group together taxa that have the greatest number of shared characteristics. This approach, also referred to as polythetic would last till evolutionary theory enabled Eichler to develop the phyletic system that superseded it in the late nineteenth century, based on an understanding of the acquisition of characteristics. He also made the crucial observation "Ex hac seminum divisione sumum potest generalis plantarum distinctio, eaque meo judicio omnium prima et longe optima, in eas sci. quae plantula seminali sunt bifolia aut διλόβω, et quae plantula sem. adulta analoga." (From this division of the seeds derives a general distinction amongst plants, that in my judgement is first and by far the best, into those seed plants which are bifoliate, or bilobed, and those that are analogous to the adult), that is between monocots and dicots. He illustrated this by quoting from Malpighi and including reproductions of Malpighi's drawings of cotyledons (see figure). Initially Ray did not develop a classification of flowering plants (florifera) based on a division by the number of cotyledons, but developed his ideas over successive publications, coining the terms "Monocotyledones" and "Dicotyledones" in 1703, in the revised version of his "Methodus" ("Methodus plantarum emendata"), as a primary method for dividing them, "Herbae floriferae, dividi possunt, ut diximus, in Monocotyledones & Dicotyledones" (Flowering plants, can be divided, as we have said, into Monocotyledons & Dicotyledons).
Post Linnean.
Although Linnaeus (1707–1778) did not utilise Ray's discovery, basing his own classification solely on floral reproductive morphology, the term was used shortly after his classification appeared (1753) by Scopoli and who is credited for its introduction. Every taxonomist since then, starting with De Jussieu and De Candolle, has used Ray's distinction as a major classification characteristic. In De Jussieu's system (1789), he followed Ray, arranging his Monocotyledones into three classes based on stamen position and placing them between Acotyledones and Dicotyledones. De Candolle's system (1813) which was to predominate thinking through much of the 19th century used a similar general arrangement, with two subgroups of his "Monocotylédonés" (Monocotyledoneae). Lindley (1830) followed De Candolle in using the terms Monocotyledon and Endogenae interchangeably. They considered the monocotyledons to be a group of vascular plants ("Vasculares") whose vascular bundles were thought to arise from within ("Endogènes" or endogenous).
Monocotyledons remained in a similar position as a major division of the flowering plants throughout the nineteenth century, with minor variations. George Bentham and Hooker (1862–1883) used Monocotyledones, as would Wettstein, while August Eichler used Mononocotyleae and Engler, following de Candolle, Monocotyledoneae. In the twentieth century, some authors used alternative names such as Bessey's (1915) Alternifoliae and Cronquist's (1966) Liliatae. Later (1981) Cronquist changed Liliatae to Liliopsida, usages also adopted by Takhtajan simultaneously. Thorne (1992) and Dahlgren (1985) also used Liliidae as a synonym.
Taxonomists had considerable latitude in naming this group, as the Monocotyledons were a group above the rank of family. Article 16 of the "ICBN" allows either a descriptive botanical name or a name formed from the name of an included family.
In summary they have been variously named, as follows:
Modern era.
Over the 1980s, a more general review of the classification of angiosperms was undertaken. The 1990s saw considerable progress in plant phylogenetics and cladistic theory, initially based on "rbcL" gene sequencing and cladistic analysis, enabling a phylogenetic tree to be constructed for the flowering plants. The establishment of major new clades necessitated a departure from the older but widely used classifications such as Cronquist and Thorne, based largely on morphology rather than genetic data. These developments complicated discussions on plant evolution and necessitated a major taxonomic restructuring.
This DNA based molecular phylogenetic research confirmed on the one hand that the monocots remained as a well defined monophyletic group or clade, in contrast to the other historical divisions of the flowering plants, which had to be substantially reorganized. No longer could the angiosperms be simply divided into monocotyledons and dicotyledons; it was apparent that the monocotyledons were but one of a relatively large number of defined groups within the angiosperms. Correlation with morphological criteria showed that the defining feature was not cotyledon number but the separation of angiosperms into two major pollen types, uniaperturate (monosulcate and monosulcate-derived) and triaperturate (tricolpate and tricolpate-derived), with the monocots situated within the uniaperturate groups. The formal taxonomic ranking of Monoctyledons thus became replaced with monocots as an informal clade. This is the name that has been most commonly used since the publication of the Angiosperm Phylogeny Group (APG) system in 1998 and regularly updated since.
Within the angiosperms, there are two major grades, a small early branching basal grade, the basal angiosperms (ANA grade) with three lineages and a larger late branching grade, the core angiosperms (mesangiosperms) with five lineages, as shown in the cladogram.
Subdivision.
While the monocotyledons have remained extremely stable in their outer borders as a well-defined and coherent monophylectic group, the deeper internal relationships have undergone considerable flux, with many competing classification systems over time.
Historically, Bentham (1877), considered the monocots to consist of four alliances, Epigynae, Coronariae, Nudiflorae and Glumales, based on floral characteristics. He describes the attempts to subdivide the group since the days of Lindley as largely unsuccessful. Like most subsequent classification systems it failed to distinguish between two major orders, Liliales and Asparagales, now recognised as quite separate. A major advance in this respect was the work of Rolf Dahlgren (1980), which would form the basis of the Angiosperm Phylogeny Group's (APG) subsequent modern classification of monocot families. Dahlgren who used the alternate name Lilliidae considered the monocots as a subclass of angiosperms characterised by a single cotyledon and the presence of triangular protein bodies in the sieve tube plastids. He divided the monocots into seven superorders, Alismatiflorae, Ariflorae, Triuridiflorae, Liliiflorae, Zingiberiflorae, Commeliniflorae and Areciflorae. With respect to the specific issue regarding Liliales and Asparagales, Dahlgren followed Huber (1969) in adopting a splitter approach, in contrast to the longstanding tendency to view Liliaceae as a very broad sensu lato family. Following Dahlgren's untimely death in 1987, his work was continued by his widow, Gertrud Dahlgren, who published a revised version of the classification in 1989. In this scheme the suffix "-florae" was replaced with "-anae" ("e.g." Alismatanae) and the number of superorders expanded to ten with the addition of Bromelianae, Cyclanthanae and Pandananae.
Molecular studies have both confirmed the monophyly of the monocots and helped elucidate relationships within this group. The APG system does not assign the monocots to a taxonomic rank, instead recognizing a monocots clade. However, there has remained some uncertainty regarding the exact relationships between the major lineages, with a number of competing models (including APG).
The APG system establishes eleven orders of monocots. These form three grades, the alismatid monocots, lilioid monocots and the commelinid monocots by order of branching, from early to late. In the following cladogram numbers indicate crown group (most recent common ancestor of the sampled species of the clade of interest) divergence times in mya (million years ago).
Of some 70,000 species, by far the largest number (65%) are found in two families, the orchids and grasses. The orchids (Orchidaceae, Asparagales) contain about 25,000 species and the grasses (Poaceae, Poales) about 11,000. Other well known groups within the Poales order include the Cyperaceae (sedges) and Juncaceae (rushes), and the monocots also include familiar families such as the palms (Arecaceae, Arecales) and lilies (Liliaceae, Liliales).
Evolution.
In prephyletic classification systems monocots were generally positioned between plants other than angiosperms and dicots, implying that monocots were more primitive. With the introduction of phyletic thinking in taxonomy (from the system of Eichler 1875–1878 onwards) the predominant theory of monocot origins was the ranalean (ranalian) theory, particularly in the work of Bessey (1915), which traced the origin of all flowering plants to a Ranalean type, and reversed the sequence making dicots the more primitive group.
The monocots form a monophyletic group arising early in the history of the flowering plants, but the fossil record is meagre. The earliest fossils presumed to be monocot remains date from the early Cretaceous period. For a very long time, fossils of palm trees were believed to be the oldest monocots, first appearing 90 million years ago (mya), but this estimate may not be entirely true. At least some putative monocot fossils have been found in strata as old as the eudicots. The oldest fossils that are unequivocally monocots are pollen from the Late Barremian–Aptian – Early Cretaceous period, about 120-110 million years ago, and are assignable to clade-Pothoideae-Monstereae Araceae; being Araceae, sister to other Alismatales. They have also found flower fossils of Triuridaceae (Pandanales) in Upper Cretaceous rocks in New Jersey, becoming the oldest known sighting of saprophytic/mycotrophic habits in angiosperm plants and among the oldest known fossils of monocotyledons.
Topology of the angiosperm phylogenetic tree could infer that the monocots would be among the oldest lineages of angiosperms, which would support the theory that they are just as old as the eudicots. The pollen of the eudicots dates back 125 million years, so the lineage of monocots should be that old too.
Molecular clock estimates.
Kåre Bremer, using rbcL sequences and the mean path length method for estimating divergence times, estimated the age of the monocot crown group (i.e. the time at which the ancestor of today's "Acorus" diverged from the rest of the group) as 134 million years. Similarly, Wikström "et al.", using Sanderson's non-parametric rate smoothing approach, obtained ages of 127–141 million years for the crown group of monocots. All these estimates have large error ranges (usually 15-20%), and Wikström "et al." used only a single calibration point, namely the split between Fagales and Cucurbitales, which was set to 84 Ma, in the late Santonian period. Early molecular clock studies using strict clock models had estimated the monocot crown age to 200 ± 20 million years ago or 160 ± 16 million years, while studies using relaxed clocks have obtained 135-131 million years or 133.8 to 124 million years. Bremer's estimate of 134 million years has been used as a secondary calibration point in other analyses. Some estimates place the emergence of the monocots as far back as 150 mya in the Jurassic period.
Core group.
The age of the core group of so-called 'nuclear monocots' or 'core monocots', which correspond to all orders except Acorales and Alismatales, is about 131 million years to present, and crown group age is about 126 million years to the present. The subsequent branching in this part of the tree (i.e. Petrosaviaceae, Dioscoreales + Pandanales and Liliales clades appeared), including the crown Petrosaviaceae group may be in the period around 125–120 million years BC (about 111 million years so far), and stem groups of all other orders, including Commelinidae would have diverged about or shortly after 115 million years. These and many clades within these orders may have originated in southern Gondwana, i.e. Antarctica, Australasia, and southern South America.
Aquatic monocots.
The aquatic monocots of Alismatales have commonly been regarded as "primitive". They have also been considered to have the most primitive foliage, which were cross-linked as Dioscoreales and Melanthiales. Keep in mind that the "most primitive" monocot is not necessarily "the sister of everyone else". This is because the ancestral or primitive characters are inferred by means of the reconstruction of character states, with the help of the phylogenetic tree. So primitive characters of monocots may be present in some derived groups. On the other hand, the basal taxa may exhibit many morphological autapomorphies. So although Acoraceae is the sister group to the remaining monocotyledons, the result does not imply that Acoraceae is "the most primitive monocot" in terms of its character states. In fact, Acoraceae is highly derived in many morphological characters, and that is precisely why Acoraceae and Alismatales occupied relatively derived positions in the trees produced by Chase "et al." and others.
Some authors support the idea of an aquatic phase as the origin of monocots. The phylogenetic position of Alismatales (many water), which occupy a relationship with the rest except the Acoraceae, do not rule out the idea, because it could be 'the most primitive monocots' but not 'the most basal'. The Atactostele stem, the long and linear leaves, the absence of secondary growth (see the biomechanics of living in the water), roots in groups instead of a single root branching (related to the nature of the substrate), including sympodial use, are consistent with a water source. However, while monocots were sisters of the aquatic Ceratophyllales, or their origin is related to the adoption of some form of aquatic habit, it would not help much to the understanding of how it evolved to develop their distinctive anatomical features: the monocots seem so different from the rest of angiosperms and it's difficult to relate their morphology, anatomy and development and those of broad-leaved angiosperms.
Other taxa.
In the past, taxa which had petiolate leaves with reticulate venation were considered "primitive" within the monocots, because of the superficial resemblance to the leaves of dicotyledons. Recent work suggests that while these taxa are sparse in the phylogenetic tree of monocots, such as fleshy fruited taxa (excluding taxa with aril seeds dispersed by ants), the two features would be adapted to conditions that evolved together regardless. Among the taxa involved were "Smilax", "Trillium" (Liliales), "Dioscorea" (Dioscoreales), etc. A number of these plants are vines that tend to live in shaded habitats for at least part of their lives, and this fact may also relate to their shapeless stomata. Reticulate venation seems to have appeared at least 26 times in monocots, and fleshy fruits have appeared 21 times (sometimes lost later); the two characteristics, though different, showed strong signs of a tendency to be good or bad in tandem, a phenomenon described as "concerted convergence" ("coordinated convergence").
Etymology.
The name monocotyledons is derived from the traditional botanical name "Monocotyledones" or "Monocotyledoneae" in Latin, which refers to the fact that most members of this group have one cotyledon, or embryonic leaf, in their seeds.
Ecology.
Emergence.
Some monocots, such as grasses, have hypogeal emergence, where the mesocotyl elongates and pushes the coleoptile (which encloses and protects the shoot tip) toward the soil surface. Since elongation occurs above the cotyledon, it is left in place in the soil where it was planted.
Many dicots have epigeal emergence, in which the hypocotyl elongates and becomes arched in the soil. As the hypocotyl continues to elongate, it pulls the cotyledons upward, above the soil surface.
Conservation.
The IUCN Red List describes four species as extinct, four as extinct in the wild, 626 as possibly extinct, 423 as critically endangered, 632 endangered, 621 vulnerable, and 269 near threatened of 4,492 whose status is known.
Uses.
Monocots are among the most important plants economically and culturally, and account for most of the staple foods of the world, such as cereal grains and starchy root crops, and palms, orchids and lilies, building materials, and many medicines. Of the monocots, the grasses are of enormous economic importance as a source of animal and human food, and form the largest component of agricultural species in terms of biomass produced.


Fine root

A fine root is most commonly defined as a plant root that is two millimeters or less in diameter. Fine roots may function in acquisition of soil resources (eg. nutrients, water) and/or resource transport, making them functionally most analogous to the leaves and twigs in a plant's shoot system. Fine-root traits are variable between species and responsive to environmental conditions. Consequently, fine roots are studied to characterize the resource acquisition strategies and competitive ability of plant species. Categories of fine roots have been developed based on root diameter, position in a root system's branching hierarchy, and primary function. Fine roots are often associated with symbiotic fungi and play a role in many ecosystem processes like nutrient cycles and soil reinforcement.
Overview.
Traditionally, scientific literature defines a fine root as a plant root with a diameter of two millimeters or less. They collectively comprise the majority of total length of a root system in many perennial and annual plants. As they age and develop, their function shifts from primarily acquiring soil resources to transporting materials to other parts of the plant body. The primary function of a fine root can be determined based on its functional characteristics.
The traits of a plant species's fine roots are thought to be indicative of that species's evolved strategy for soil resource acquisition. Certain characteristics of fine-root growth and physiology are highly plastic, however, allowing a plant's roots to respond to the nature of the local soil environment. Fine roots have been shown to respond to soil nutrient patches. Responses include the lengthening of root segments and increased total length of fine roots, increased initiation of lateral roots, and increased branching. The effect of these responses on a plant's nutrient uptake is unclear. In multiple ecosystem types and forest stand ages, fine-root biomass has been found to decrease with increasing soil depth. Similarly, fine-root nitrogen concentration has been shown to be lower in deeper soil. These shifts may reflect vertical changes in the nature of soil, as shallow soils may have greater available nutrient content than deep soils. Features that appear to be lateral branch scars have been observed on fine roots, indicating that some fine roots are deciduous.
Classification.
Traditionally, fine roots are defined as plant roots with a diameter of two millimeters or less. This size-based definition is arbitrary, as it does not clearly or logically define fine roots based on anatomy, morphology, physiology, and/or function. Early studies that used this definition assumed that all roots in the two millimeter size class are functionally alike, but many successive studies have shown that roots in this size class can have different demographic and functional traits.
Within the two millimeter size class, roots can be highly variable in characteristics and function. To account for this, root biologists have begun to define subcategories of fine roots based on root diameter, position in the root branching hierarchy, and function.
Diameter-based classes.
As a group, fine roots are most consistently defined by the diameter cutoff of two millimeters. In recognition of the variety of root traits and functions within this category and the relationship between diameter and function, smaller diameter classes have been used in recent research. Studies focusing only on roots that function in resource acquisition have examined roots under one millimeter or 0.5 millimeters. Roots with a diameter less than 0.5 millimeters have been termed 'very fine roots'. Because fine-root traits like diameter vary by species, and research examining the function of different root sizes in different species is limited, diameter-based classes of fine roots are mostly arbitrary and complicate cross-species comparisons. For example, two-millimeter-diameter fine roots may occur in trees, but would be very large roots in many annual and perennial species of crops.
Order-based classes.
This classification system assigns an order number to a root based on that root's position in the branching hierarchy of the root system, and is based on the Horton-Strahler scheme for ordering stream tributaries. The most distal segments of the root system (unbranched root segments that end in root tips) are classified as first-order roots. When two roots of the same order converge, the root that results from their combination is assigned the next highest root order (so two first-order roots merge to form a second-order root). When two root segments of different orders meet, the resulting root is given the higher order of the two roots that merged (so a second-order and a first-order root combine to form a second-order root). This classification system is common in modern root research, as many studies have shown that significant differences in fine-root traits can be detected when distinguishing roots by order. Traits that have been shown to increase with root order include root diameter, life span, and secondary growth, while root nitrogen content, mycorrhizal colonization, and turnover have shown decreases with increasing root order.
Function-based classes.
By this system, fine roots are classified as either absorptive fine roots or transport fine roots. Absorptive fine roots mostly function in acquiring soil resources and comprise the most distal segments of a root system (lower-order segments). Transport fine roots result from the merging of absorptive fine roots and are therefore higher in root order. Primarily, transport fine roots transport plant materials and support plant structure, but may also store plant materials. These functional classes can often be distinguished visually in trees, but not in crops.
Ecology.
Mycorrhizal associations.
In trees, fine roots are generally exclusively or dominantly colonized by a single mycorrhizal type, either arbuscular mycorrhizae or ectomycorrhizae.
Competition.
Plants often compete with surrounding plants for root space and resources. A plant's ability to compete, and strategy for competition, can be determined by examining the traits, abundance, distribution, and functions of fine roots and their associated mycorrhizas.
Material cycling.
In terrestrial environments, fine roots absorb water and nutrients from soil, and return such resources to the soil upon death and decomposition. Fine roots also release exudates, including labile carbon, during life processes and turnover. This directly affects soil organic carbon pools, and indirectly affects them by stimulating microbial activity. Therefore, fine roots play a role in water, carbon, and nutrient cycles of terrestrial ecosystems. In forest carbon and nutrient cycles, the formation, death, and decomposition of fine roots can account for 20-80% of total net primary production.
Soil reinforcement.
Plant roots support soil, which stabilizes sloped landscapes and limits soil erosion. Root size properties, including diameter, influence the mechanical reinforcement of a slope. Soil stability depends on root tensile strength. Root tensile strength increases with decreasing root diameter, so fine roots are stronger than coarse roots.


Coprosma tenuicaulis

Coprosma tenuicaulis, commonly called swamp coprosma is a native shrub of New Zealand. As its name suggests "C. tenuicaulis" is found in wet, boggy soil in and around swamp or lake areas.
The shrub flowers in early spring and produces black/red fruit that ripen between February and June.


Laminariales


Sclerolepis

Sclerolepis is an aquatic plant native to the eastern United States. It has only one known species, Sclerolepis uniflora, the pink bogbutton. It lives in ponds and other wet areas. When water is abundant, the plant lives underwater, with long stems and flaccid, elongated leaves, and does not flower. When the water level drops, it assumes a form more familiar in terrestrial plants, with an erect stem, and flowers in summer to fall. The flowers are pink.
"Sclerolepis" is fairly common in the southeastern United States, from Alabama and Florida to North Carolina, and has more sparse distribution as far north as New Hampshire.
Classification.
"Sclerolepis" is in the tribe Eupatorieae of the aster family. It is thought to be related to two other aquatic genera in this tribe, "Shinnersia" and "Trichocoronis".


Trinidad and Tobago moist forests

The Trinidad and Tobago moist forests ecoregion (WWF ID:NT0171) covers most of Trinidad Island and Tobago Island near the coast of South America where the southeastern Caribbean Sea meets the Atlantic Ocean. Small portions of the islands around river estuaries and coastal lowlands are mangroves or dry forests. Species diversity is very high, in particular for plants (over 2,500 species) and birds (over 400 species). Tobago, being much smaller, has fewer species.
Location and description.
Approximately 90% of islands are in this ecoregion. There are a few scattered mangroves of the Trinidad mangroves ecoregion at the main river estuaries, a ring of dry forest of the Trinidad and Tobago dry forests ecoregion around the Caroni Swamp, just south of the capital city of Port of Spain, and a small section of dry forest at the northeast end of Tobago. The islands are affected by the South Equatorial Current from the southeast and the outlflow from the Orinoco River to the south. Elevations in the islands are .
Climate.
The climate of the ecoregion is "Tropical monsoon climate" (Köppen climate classification (Am)). This climate is characterized by relatively even temperatures throughout the year (all months being greater than average temperature), and a pronounced dry season. The driest month has less than 60 mm of precipitation, but more than (100-(average/25) mm. This climate is mid-way between a tropical rainforest and a tropical savannah. The drier months are in the winter.
Flora and fauna.
The island of Trinidad is only 20 km from the mainland of South America, and a land bridge existed as late as 1,500 years ago. So the flora and fauna are most similar to those of the continent. The island of Tobago is a further 40 km from the northern edge of Trinidad, and its land bridge disappeared 11,500 years ago, but its species mix is similar to the larger island. Over 60% of the island is still covered with closed broadleaf evergreen forest.
The islands have high species diversity, with over 2,500 species of plants identified, of which up to 110 are endemic to the island. Also reported 100 species of mammals (bats and rodents predominate), 400 of birds, 85 of reptiles, and 30 of amphibians. Characteristic tree species are andiroba ("Carapa guianensis"), andiroba ("Ceiba pentandra"), yellow mombin ("Spondias mombin"), "Pentaclethra macroloba", and "Brownea latifolia". A notable tree species in eastern Trinidad is the "Mora" tree.
Protected areas.
Officially protected areas in the ecoregion include:


Diospyros major

Diospyros major, or the Fiji persimmon, is a tree in the family Ebenaceae that is native to Fiji, Tonga, Uvea, and Futuna. It is called 'mapa in the Tongan language.


Leptobryum

Leptobryum is a genus of mosses belonging to the family Bryaceae.
The genus has cosmopolitan distribution.
Species:


Leskea

Leskea is a genus of mosses belonging to the family Leskeaceae.
The genus has cosmopolitan distribution.
Species:


Preissia

Preissia is a genus of liverworts in the order Marchantiales. It is a member of family Marchantiaceae within that order. This genus has a worldwide distribution.


Synechanthus

Synechanthus is a monoecious genus of flowering plant in the palm family found in Mexico, Central and South America. Commonly called bola, palmilla, or jelly bean palm, they are closely related to members of "Chamaedorea", only distinguished by their flower and fruit form. The Greek genus name is a combination of "united" and "flower".
Description.
"Synechanthus fibrosus" is solitary while "S. warscewiczianus" is clustering. The trunks of both are slender, rarely more than 2.5 cm wide, growing to 4.5 m tall; usually dark green, they are ringed by white leaf scars. "S. warscewiczianus" will usually have a dominant main stem with smaller clustering units surrounding it. The pinnate leaf is over a meter long, borne on a 30 cm petiole; the rachis is angled above and rounded below, the leaflets are slightly offset, occasionally twisting, the apical set being widest.
The inflorescence emerges in the leaf crown but sags pendent in fruit, once or twice branched and solitary. The peduncle is long and the prophyll short and tubular, disintegrating into a fibrous mass at the base. There are four to five peduncular bracts, longer than the prophyll, with the distalmost exceeding the peduncle. The rachis is elongated bearing slender rachillae with slender, spinelike tips. The flowers are arranged on the rachillae such that the pistillate members are proximal, with 5 - 13 staminate flowers at the distal end.
The staminate flowers mature from green to yellow, triangular in bud, with three sepals fused into a lobed cupule and three valvate petals. They carry three or six stamens on short, recurved filaments with basifixed, latrose anthers with elliptic, monosulcate pollen and scabrate, tectate exine. The pistillode, when present, is small, ovoid and three lobed. The pistillate flowers are also yellow with three cupped sepals and three longer, imbricate petals. When staminodes are present there are three, joined in a ring; the gynoecum is ovoid, triocular and triovulate. The three stigmas are recurved with elongated, laterally attached ovules. The large fruit is round or slightly egg shaped, maturing to bright red or orange in color, with a fleshy mesocarp and a membranous endocarp. The single seed has homogeneous endosperm and a centrally placed embryo.
Distribution and habitat.
"Synthechanthus" palms are found in Mexico, Guatemala, Honduras, Nicaragua, Costa Rica, Panama, Colombia and Ecuador. They are rain forest inhabitants, usually confined to the understory, from sea level to 1200 m.
Cultivation.
Both are cultivated as ornamentals, requiring rain forest-like conditions to thrive, shade or filtered light, humus-rich, friable soil and copious amounts of quickly-draining water; neither is hardy to cold, requiring protection from freezing temperatures.


Kokoona

Kokoona is a genus of plants in the family Celastraceae.
Species include:


Faba bean necrotic stunt virus

"Faba bean necrotic stunt virus" (FBNSV) is a pathogenic plant virus of the family "Nanoviridae". Its infection cycle is remarkable because it has eight segments, each carried in a different particle, that can replicate independently in different host cells and then reassemble outside of the host cells into new complete virions.


Schizomeridaceae

Schizomeridaceae is a family of algae in the order Chaetophorales.


Meterostachys

Meterostachys is a genus of plants in the family Crassulaceae, that contains a single accepted species, Meterostachys sikokiana, native to Japan and Korea. It is little known and is difficult to cultivate.


Abelia

Abelia is a formerly recognized genus that contained about 30 species and hybrids, placed in the honeysuckle family, Caprifoliaceae. Molecular phylogenetic studies showed that the genus was not monophyletic, and in 2013, Maarten Christenhusz proposed the merger of "Abelia" (excluding section "Zabelia") into "Linnaea", along with some other genera. "Abelia" section "Zabelia" was raised to the genus "Zabelia".
Description.
Species formerly placed in "Abelia" are shrubs from 1–6 m tall, native to eastern Asia (Japan west to the Himalaya) and southern North America (Mexico); the species from warm climates are evergreen, and colder climate species deciduous. The leaves are opposite or in whorls of three, ovate, glossy, dark green, 1.5–8 cm long, turning purplish-bronze to red in autumn in the deciduous species. The flowers appear in the upper leaf axils and stem ends, 1-8 together in a short cyme; they are pendulous, white to pink, bell-shaped with a five-lobed corolla, 1–5 cm long, and usually scented. Flowering continues over a long and continuous period from late spring to fall.
Some of these species are cultivated as ornamental garden plants, and may still be described as "Abelia" in horticultural listings. A notable example is the hybrid "Abelia" × "grandiflora" (now "Linnaea" × "grandiflora").
Taxonomy.
The generic name commemorates Clarke Abel, a keen naturalist who accompanied Lord Amherst's unsuccessful embassy to China in 1816 as a surgeon, under the sponsorship of Sir Joseph Banks. All of Abel's seeds and plants were lost in a shipwreck on the homeward voyage, however; living plants of "Abelia chinensis" (now "Linnaea chinensis") were first imported to England in 1844 by Robert Fortune.
Some species placed in "Abelia" were transferred to "Linnaea" at various times from 1872 onwards, but these transfers were not accepted by most botanists. Molecular phylogenetic studies showed that a number of genera traditionally placed in the tribe Linnaeeae were closely related, but that "Abelia" was not monophyletic, even with "Abelia" section "Zabelia" split off as a separate genus "Zabelia". In 2013, Maarten Christenhusz proposed that "Abelia" and related genera be merged into "Linnaea". This proposal has been adopted by recent sources, including the Plants of the World Online.
Allergenicity.
"Abelia" has an OPALS allergy scale rating of 5, indicating moderate potential to cause allergic reactions, exacerbated by over-use of the same plant throughout a garden. People allergic to honeysuckle may experience cross-reactive allergic reactions with "Abelia".
Symbolism.
The Abelia is symbolic for equality in some parts of Mexico
Former species and synonyms.
Species and synonyms previously placed in "Abelia" but now placed in other genera include:


Ankerwycke Yew

The Ankerwycke Yew is an ancient yew tree close to the ruins of St Mary's Priory, the site of a Benedictine nunnery built in the 12th century, near Wraysbury in Berkshire, England. It is a male tree with a girth of at 0.3 metres. The tree is at least 1,400 years old, and could be as old as 2,500 years.
On the opposite bank of the River Thames are the meadows of Runnymede and this tree is said to have been witness to the signing of "Magna Carta". The tree is also said to be the location where Henry VIII courted Anne Boleyn in the 1530s.
There is some justification for the theory that the Ankerwycke Yew could be "the last surviving witness to the sealing of the "Magna Carta" 800 years ago". "In the 13th century, the landscape would have been different as the area was probably rather marshy as it was within the flood plain of the Thames. The Ankerwycke Yew is on a slightly raised area of land (therefore dry) and with the proximity of the Priory perhaps both lend some credibility to this claim."
The Ankerwycke Yew is situated on lands managed by the National Trust. In 2002 it was designated one of fifty Great British Trees by The Tree Council.


Eucalyptus doratoxylon

Eucalyptus doratoxylon, commonly known as the spearwood mallee, spearwood or geitch-gmunt in Noongar language is a species of mallee that is endemic to Western Australia. It has smooth, powdery white bark, lance-shaped to curved adult leaves mostly arranged in opposite pairs, flower buds in groups of seven, white to pale yellow flowers and pendulous, more or less spherical fruit.
Description.
"Eucalyptus doratoxylon" is a mallee, rarely a small tree, that typically grows to a height of and forms a lignotuber. It has smooth, powdery white over reddish or greenish bark. Young plants and coppice regrowth have narrow elliptic to narrow lance-shaped leaves that are arranged in opposite pairs, long and wide. Adult leaves are also usually arranged in opposite pairs, glossy green, long and wide on a petiole long. The flower buds are arranged in groups of seven in leaf axils on an unbranched peduncle long, the individual buds on a pedicel long. Mature buds are pear-shaped to oval, creamy white, long and wide with a beaked operculum. Flowering occurs between August and March and the flowers are white to pale yellow. The fruit is a pendulous, woody, more or less spherical capsule long and wide with the valves near rim level.
Taxonomy.
"Eucalyptus doratoxylon" was first formally described in 1860 by the botanist Ferdinand von Mueller in "Fragmenta Phytographiae Australiae" from samples collected by George Maxwell in the Kojoneerup district.
The specific epithet is ("doratoxylon") is derived from the Ancient Greek words "dory, doratos" meaning "spear" and "xylon" meaning "wood", possibly in reference to the use of the stems for spears.
Distribution.
Spearwood mallee grows in sandy loam or white-grey sandy soils in heath and open forest on hills and around granite outcrops along the south coast in the Esperance Plains, Jarrah Forest and Mallee biogeographic regions of Western Australia.
Conservation status.
"Eucalyptus doratoxylon" is classified as "not threatened" by the Western Australian Government Department of Parks and Wildlife
Noongar Uses.
Noongars used the branches to make spears: the bends in the branch were straightened over fire and the tips were sharpened using a chert flake.
As with all other Eucalypts in the south-western region of Western Australia, the leaves of this species were crushed to make antibacterial poultices for wounds. They were also crushed and steamed to relieve nasal congestion. The gum was used after grinding, to make an ointment for sores, and also taken orally as a treatment for dysentery.


Conostylis albescens

Conostylis albescens is a rhizomatous, tufted perennial plant species in the family Haemodoraceae, endemic to the south-west of Western Australia. Plants grow to between 12 and 17 cm high and produce yellow-cream-white flowers in August in the species' native range. The grey-green, hairy, leaves are 12–17 cm long and 0.8–1.5 mm wide.
It is found east of Merredin, Western Australia, on yellow sandplain in a small region of heath.
It was first described in 1987 by Stephen Hopper as "Conostylis albescens".


Heliotropium riebeckii

Heliotropium riebeckii is a species of plant in the family Boraginaceae. It is endemic to Yemen. Its natural habitats are subtropical or tropical dry shrubland and subtropical or tropical wet lowland grassland.


Boswellia dalzielii

Boswellia dalzielii is a tree species in the genus "Boswellia" found in Africa. The bark of this plant is used in traditional medicines.
Gallic and protocatechuic acids were isolated as the main antibacterial and antioxidant principles of the stem bark of "B. dalzielii". 4'-Methoxy-(E)-resveratrol 3-O-rutinoside, incensole and b-sitosterol were also isolated.


Noel T. Keen

Noel Thomas Keen (August 13, 1940 – April 18, 2002) was an American plant physiologist. He spent his career teaching at University of California, Riverside (UCR). His research focused on the varied ability of cultivars to detect and resist pathogens.
Early life and education.
Noel Keen was born in Marshalltown, Iowa and grew up on a farm, attending a rural school. He first attended high school in LaMoille, Iowa where he played basketball until the school was absorbed into the high school in State Center. At State Center he competed on the debate team until he graduated in 1958. Keen attended Iowa State University in Ames, Iowa, where he earned both his bachelor's and master's degrees. His master's thesis discussed the impact of "Pyrenochaeta terrestris" on onions. Keen was awarded his Ph.D from University of Wisconsin–Madison. He published 12 separate documents based on his thesis work, which merited him a job teaching at University of California, Riverside (UCR) despite not having any postdoctoral experience.
Career.
Keen arrived at UCR in 1968 and was promoted to associate professor in plant pathology in 1972. Keen studied the biochemical interactions responsible for resistance to "Phytophthora sojae" in one cultivar of soybean but not another, publishing the first findings on the subject in 1975. He coined the term "elicitor" to describe the chemicals given off by invading organisms that elicited phytoalexin response in the host plant. This work led him to identify the single gene in "Pseudomonas syringae" responsible for producing elicitors. Since 1977 Keen spoke at many National Science Foundation-funded international conferences, particularly with the Japanese scientists like Masaaki Yoshikawa. In 1997 Keen co-founded Connecting Research and Economic Development for the 21st Century (CORE21), a business-academia collective. He served on its board of directors until 2002.
Awards and honors.
In 1995 Keen was awarded the American Phytopathological Society's annual award, named after Ruth Allen (herself a plant pathologist), alongside fellow professor Brian Staskawicz. The two had worked together in 1980 at the International Plant Research Institute in San Carlos, California in order to use recombinant DNA techniques to clone bacterial avirulence genes. Their work confirmed an aspect of the Gene-for-gene relationship.
Keen was elected to the National Academy of Sciences in 1997. In 2000, an image of Keen standing next to the parallel β-helix structure of pectate lyase C was added as part of the Gluck Gateway Mural positioned under the California State Route 60 overpass between the University campus and the city of Riverside. Keen had discovered the parallel helix to be pectate lyase C's third folding form during a collaboration with X-ray crystallographers studying "Erwinia chrysanthemi".
The American Phytopathological Society awards an annual cash prize in Keen's name for "research excellence in molecular plant pathology." University of California, Riverside hosts an annual lecture named for Keen focusing on plant biology and pathology. The lecture series is endowed by the Noel T. and Diane Ill Keen Fund. In 2003 University of California, Riverside named their renovated bio-agricultural library "Noel T. Keen Hall." Keen Hall houses UCR's stem cell research center.
Death.
Keen was the victim of a 1999 car crash. Subsequent to the crash, blood tests revealed Keen had leukemia. He remained active until weeks before his death in 2002.


Nardia huerlimannii

Nardia huerlimannii is a species of liverwort in the family Solenostomataceae. It is endemic to New Caledonia. Its natural habitat is subtropical or tropical dry forests.


Alkanet

Alkanet is the common name of several related plants in the borage family (Boraginaceae):


Caulanthus coulteri

Caulanthus coulteri is a species of flowering plant in the family Brassicaceae known by the common name Coulter's wild cabbage.
It is endemic to California, where it is a widespread member of the flora in several dry, open habitat types, such as chaparral and Mojave Desert.
Description.
"Caulanthus coulteri" is a tall annual herb producing a slender, branching stem lined with generally lance-shaped leaves which may be smooth to sharply sawtoothed along the edges.
The widely spaced flowers are somewhat bullet-shaped with coats of pouched sepals which are bright to deep purple when new and fade to yellow-green. The sepals open to reveal dark-veined petal tips with wavy margins.
The fruit is a long, thin silique which may approach 13 centimeters in length.


Sedum laxum

Sedum laxum is a species of flowering plant in the family Crassulaceae known by the common name roseflower stonecrop. It is native to southwestern Oregon and northwestern California, where it can be found in rocky mountainous habitat. It is a succulent plant forming basal rosettes of oval or oblong leaves up to 3 centimeters long. The inflorescence is made up of one or more erect arrays of many flowers. The flowers have reddish or yellowish petals up to 1.3 centimeters long each.


Boechera pulchra

Boechera pulchra, the beautiful rockcress, is a perennial plant in the mustard family (Brassicaceae) found in the Mojave Desert and other dry regions of southern and eastern California and Nevada, and the Colorado Plateau and Canyonlands region of the southwestern United States, mostly below elevation.
Description.
A long-lived perennial, it is usually tall from a woody base. Eight to twenty purple, rarely white, flowers are borne in a normally unbranched raceme. Petals are long and wide. Sepals are hairy.


Geppella

Geppella is a genus of green algae in the family Codiaceae.


Alyxia squamulosa

Alyxia squamulosa, commonly known as alyxia vine, is a species of shrub in the family Apocynaceae. It is endemic to Australia’s subtropical Lord Howe Island in the Tasman Sea. The specific epithet derives from the many bracteoles, or ‘scales’ (Latin: "squamae", with the diminutive suffix -"ulus") that subtend the flowers. The plant previously known as "Alyxia lindii" is considered a taxonomic synonym of A. squamulosa, being reassigned in 2002.
Description.
The plant has a tendency to climb. Its leaves grow in whorls of five and are 2–5 cm long, 1.5–2.5 cm wide. The fetid white flowers are about 7 mm long, clustered in dense, rounded, terminal inflorescences 2–4 cm in diameter. The fruits are drupaceous, blue-black and about 2 cm long.
Distribution and habitat.
The plant is found only on Lord Howe Island, on the lower hills of the island, as well as the higher southern peaks.


Sunn-hemp mosaic virus

Sunn-hemp mosaic virus (SHMV) is a pathogenic plant virus. It is known by many names, including bean strain of tobacco mosaic virus and Sunn-hemp rosette virus. SHMV is an intracellular parasite that infects plants. It can be seen only through an electron microscope. It is a positive-sense single-stranded RNA virus that causes physical characteristics of spotting and/or discoloration. The Sunn-hemp mosaic virus is listed as a species within the genus "Tobamovirus" and the virus family "Virgaviridae" by the International Committee on the Taxonomy of Viruses, who renamed it from "Sunnhemp" to "Sunn-hemp" in 1991.
Transmission.
Infected crops transmit the virus in a number of ways, but in most cases transmittal requires physical contact. This mean that touching an infected plant, then touching a healthy plant could cause the healthy plant to contract the virus. Using tools to trim an infected plant, then using them on a healthy plant without sterilizing them between uses can result in the transmission of the virus. The virus should be treated like it is airborne since an insect can transmit the virus, from plant to plant, just by flying around and making contact between plants. Hemp mosaic virus is particularly resilient and can infect the soil through the winter and into the following growing seasons for years.
Effects.
The Sunn-hemp mosaic virus should not be confused with the hemp mosaic virus. The virus causes cellular mutations, stunted growth, damages plants photosynthesis ability, and more. Cellular mutations usually manifest as discoloration and misshapen leaves. Discoloration usually manifests as yellow or grey mottling that can form a spotted, mosaic, or streak pattern. Misshapen leaves can be the result of damage to the plants at a cellular level, making them appear contorted and/or twisted. The stunted growth can cause a tremendous amount of crop loss due to lower than normal yields. Losses of 25% of flower production or more have been widely observed and reported.
Treatment.
There is no known cure for the hemp mosaic virus or other tobamoviruses. Once a plant has become infected with the virus the host will never be free from infection. The virus is destroyed through incineration of the infected tissues. Plants do have a natural defense in the form of a protein coating that protects the plants RNA. Different strains have varying resiliencies to hemp mosaic virus due to varying levels of the hormone responsible for the production of the protective protein coatings.
Environment.
Hemp mosaic virus is known as one of the most stable viruses. It has a very wide survival range. As long as the surrounding temperature remains below approximately 40 degrees Celsius, hemp mosaic virus can sustain its stable form. All it needs is a host to infect. Greenhouses and botanical gardens would provide the most favorable condition for the virus to spread, due to the high population density of possible hosts and the constant temperature throughout the year.
The virus "occurs naturally in leguminous plants in Australia, India, Nigeria, and the United States" and has been described with a variety of names based on the host from which it was isolated. It has been observed to infect more than 40 host species across seven different families of plant.


Austrobuxus

Austrobuxus is a genus of plants under the family Picrodendraceae first described as a genus in 1861. It is native to Southeast Asia, Papuasia, and Australia. The region with the highest diversity is New Caledonia.
moved to other genera: "Kairothamnus Longetia Scagea"


Dichanthelium scoparium

Dichanthelium scoparium is a species of grass known by the common names velvet panicum, velvety panicgrass, and broom panicgrass. It is native to North America, where it occurs in the southeastern United States. It also occurs in the West Indies.
This rhizomatous perennial grass produces a basal rosette of leaves in the fall and winter and then erect stems the following spring. There are clumps of stems up to 1.5 meters tall. There are 7 to 11 hairy leaves up to 20 centimeters long by 2 wide on the stem. There are two types of inflorescence. The main panicle has flowers that open and are pollinated. There are also cleistogamous flowers that do not open and fertilize themselves. These develop later in the season. There are about 380,000 seeds per pound.
This grass grows in woodlands and savannas. It may inhabit disturbed habitat.


Brachynema axillare

Brachynema axillare is a dicotyledonous plant species described by R. Duno de Stefano and Paul Edward Berry. "Brachynema axillaries" is part of the genus "Brachynema" and the family Olacaceae. No subspecies are listed in the Catalog of Life.


Gentiana austromontana

Gentiana austromontana, the Appalachian gentian, is a tall flowering plant in the Gentianaceae family. It is native to the southern Appalachians of West Virginia, Virginia, North Carolina and Tennessee. Very similar to "Gentiana clausa", it has paired, lanceolate leaves, usually on unbranched stalks, and blue or purple blooms which remain closed or nearly closed. It flowers from late August to October. It is thought that "G. austromotana" is the product of hybridization between "G. clausa" and "G. decora" as the Appalachian Gentian is found only in area where the former two are sympatric.


Zeltnera venusta

Zeltnera venusta is a species of flowering plant in the gentian family known by the common names California centaury, charming centaury and canchalagua. This centaury is native to much of California, southern Oregon, and northwest Baja California.
It grows in many habitats up to elevations around 1300 meters. It is an annual wildflower rarely reaching half a meter in height. The pointed oval leaves grow opposite on the thin stems. The inflorescence is tipped with one or more showy star-shaped flowers, each with a white-centered magenta corolla about 2 centimeters wide.
Until 2004, it was placed in genus "Centaurium" as "Centaurium venustum".


Frailea chiquitana

Frailea chiquitana is a species of Frailea from Bolivia.


Clematis crispa

Clematis crispa is a species of flowering plant in the buttercup family known by the common name swamp leatherflower. It is found in southeastern United States.


Gahnia filum

Gahnia filum, the chaffy saw-sedge, is a tussock-forming perennial in the family Cyperaceae, endemic to Australia. It grows to between 60 and 110 cm in height.
The species occurs in coastal salt marsh in the states of New South Wales, Victoria, Tasmania and South Australia.
The caterpillar of the yellow sedge-skipper butterfly uses this species for shelter during daylight hours, binding the leaves with silk. By night it feeds on the grass. "Ghania" is being planted at Aldinga Washpool in South Australia in order to provided habitat for the endangered butterfly.


Passiflora quetzal

Passiflora quetzal is a species of flowering plant native to Mexico and Guatemala described in 2004. It is named after the quetzal, which inhabits the area.
Taxonomy.
"Passiflora quetzal" has been assigned to supersection "Hahniopathanthus" in subgenus "Decaloba".
Distribution and habitat.
"Passiflora quetzal" is native to Southwestern Chiapas, Mexico, and western San Marcos, Guatemala. It has been found growing at 1800–2400 metres in wet mountain forest.
Description.
The vine is glabrous. The stems are terete and glaucous. Stipules are 10-19 × 10-20mm, depressed ovate, auriculate, clasping, widely obtuse, abruptly acute and apiculate-mucronlate to abruptly long-acuminate, and the margin entire to obscurely crenulate and 8-15 glandular. Petioles are (1-)2- glandular near or proximal to the middle. Nectaries are 0.6-0.8 × 0.4-0.9 mm. Blades are 7-11.5 × 7.5-11.5 cm, subpeltate 2-3(-3.5) mm from the margin, entire or glandular-denticulate at the very base, not variegated at maturity, very widely obovate to widely elliptic or ± circular, at base extremely shallowly cordate to truncate or slightly rounded. Leaves are shallowly to obscurely 3-lobed, with lateral lobes that are broadly obtuse to rounded or nearly obsolete, and a central lobe that is obtuse or somewhat rounded to truncate. Laminar nectaries are marginal, with 4 or 5 gland borne basally, (0)1 to 8 glands borne just proximal to the lateral veins, and (0)2 to 8 glands borne marginally distal to the lateral veins. Penduncles are (1)2 per node, 3.6-5.8 cm, and uniflorous. There are 2 bracts at the apex of the peduncle, which are 0.9-1.3 × 1.0-1.3 cm, ovate to widely ovate-oblong, cordate, free to the base, entire, 6- to 12-glandular marginally, obtuse to rounded, apiculate or abruptly long-acuminate, and light green. Flowers are white to green-white; stipe 2.5–5 mm; hypanthium diameter about 15 mm; sepals 18-20 × 9–10 mm, oblong to triangular, rounded at apex; petals 12 × 7 mm, ovate and narrowed at the base; coronal filaments in 2 to 3 series, the outermost 16–20 mm and filiform, the inner 1 to 2 series 7–10 mm; operculum 4.5-5.0 mm, membranous, plicate; limen edge at least 1.5 mm high; androgynophore 8.5–9 mm, free staminal filaments about 6 mm, anthers about 5 mm; ovary 3.8-4.0 × 2.3-2.5 mm, ovoid elipsoid, glabrous; styles at least 9 mm long including stigmas. The fruit is about 6 × 3.5 cm, ellipsoid, with stipe absent or less than 4 mm; seeds 5.3-6.0 × 3.5-3.9 × 2.0 mm. obovate in outline, campylotropous, the testa reticulate with about 50 to 60 pits, the chalazal beak include toward the raphe.
While there are many marginal laminar nectary glands located at the base of the lamina and marginally on the leaf between primary veins, smaller leaves tend to lack some marginal nectaries. The flowers are similar to those of "Passiflora guatemalensis" and to some forms of "Passiflora hahnii". The bracts are smaller, however. The species resembles some examples of "Passiflora membranacea".


Martensia fragilis

Martensia fragilis is a species of red algae.


Lophozia

Lophozia is a genus of liverworts belonging to the family Jungermanniaceae.
The genus was first described by Barthélemy Charles Joseph Dumortier.
The genus has cosmopolitan distribution.
Species:


Psammomoya choretroides

Psammomoya choretroides is a small shrub in the Celastraceae family, endemic to the south west of Western Australia. It was first described by Ferdinand von Mueller in 1889 as "Logania choretroides", but was transferred to the genus, "Psammomoya", in 1904 by Ludwig Diels and Ludwig Eduard Theodor Loesener.
Description.
Mueller described it as follows:
Etymology.
Mueller considered the plant to be like a "Choretrum", and hence described it using the species epithet, "choretroides" ("Choretrum-like").


Najas

Najas, the water-nymphs or naiads, is a genus of aquatic plants. It is cosmopolitan in distribution, first described for modern science by Linnaeus in 1753. Until 1997, it was rarely placed in the Hydrocharitaceae, and was often taken as constituting (by itself) the family "Najadaceae".
The APG II system, of 2003 (unchanged from the APG system, of 1998), places the genus in family Hydrocharitaceae, in the order Alismatales of the monocots.
An infrageneric classification of two sections is proposed: Section "Americanae" and sect. "Caulinia".


Apium prostratum subsp. howense

Apium prostratum" subsp. "howense is a flowering plant in the carrot family. The subspecific epithet refers to the island to which it is endemic.
Description.
It is a perennial herb, tufted, trailing and aromatic when bruised, with stems growing to 30 cm long. The pinnate leaves are 20–170 mm long. The tiny flowers are white to pinkish. The fruits are 1.5–2 mm across.
Distribution and habitat.
The subspecies is endemic to Australia’s subtropical Lord Howe Island in the Tasman Sea. There it is fairly common in sand pockets and cracks in coralline rocks on the shoreline, within the splash zone. Joseph Maiden's 1889 book 'The Useful Native Plants of Australia records how 'Apium australe' could be used as a culinary vegetable and also refers to it as 'Australian Celery".


Gymnosiphon suaveolens

Gymnosiphon suaveolens is a flowering plant that can be found from Mexico to Ecuador and Venezuela. It mostly grows in tropical rainforests and lives parasitically on fungus to survive. It can remain underground for many years, emerging only when the conditions are right to flower and fruit.


Dacryodes nervosa

Dacryodes nervosa is a tree in the family Burseraceae. The specific epithet "" is from the Latin meaning "with nerves", referring to the leaves.
Description.
"Dacryodes nervosa" grows up to tall with a trunk diameter of up to . The dark brown bark is smooth to scaly. The ellipsoid fruits are pink when fresh and measure up to long.
Distribution and habitat.
"Dacryodes nervosa" grows naturally in Sumatra, Peninsular Malaysia and Borneo. Its habitat is lowland forest from sea-level to altitude.


Cheniella

Cheniella is a genus of flowering plants in the legume family, Fabaceae. It belongs to the subfamily Cercidoideae. This genus differs from "Phanera" in having a hypanthium that is equal in length or longer than the sepals, indehiscent fruit, many-seeded fruit, and the funicle extending most of the circumference of the seed.
Species.
"Cheniella" comprises the following species:


Centropogon ursinus

Centropogon ursinus is a species of plant in the family Campanulaceae. It is endemic to Ecuador. Its natural habitat is subtropical or tropical moist montane forests.


Solanum betaceum


Polygala lutea

Polygala lutea, commonly known as orange- or yellow milkwort, is a plant in the milkwort family (Polygalaceae) native to pine-barren depressions and swamps in costal areas of the southern and eastern the United States. It was first described in 1753 by Carl Linnaeus.
Description.
"Polygala lutea" is an annual or biennial herbaceous plant which has a height between . Its flowers are orange-yellow and long. Its pedicels are long. It flowers between April and October.


Gaultheria insipida

Gaultheria insipida, called chichaja in Spanish, is a flowering shrub of the plant genus "Gaultheria". The species is native to the Andes; specimens have been found in Colombia, Ecuador, and Peru.
This semi-hardy shrub grows to a height of . Its long, thin branches bear bright green leaves, which may grow up to long. In autumn, the leaves turn a burgundy colour, and the shrub's pink flowers mature into small, white berries topped with five red spots.
Two varieties have been described: "G. insipida insipida" and "G. insipida peruviana". James Francis Macbride found the latter in the Huánuco Region of central Peru, and published his description in 1959.
Inga traditional medicine.
In the Putumayo department of southwestern Colombia, the Inga people treat chronic pain and other conditions with a drink by simmering the root of the plant in water for several hours.
For myalgia (body ache), low energy/motivation, and hypersomnia, the patient drinks an infusion of chichaja. The infusion is also said to cleanse the blood and to help prevent disease. In cases of rheumatism, chronic fatigue, or hemorrhoids, the patient drinks the infusion hot.
For malaise, the patient drinks a decoction of , ("Eugenia victoriana"), , (a Rubiaceae species), "Peperomia", and chamomile three times per day.
The Ingas prepare an infusion of , , and chichaja in the belief that it promotes the purging of toxins through the sweat glands.
In Colombia, is sometimes called yagé hembra ("female ayahuasca"), whereas in Peru this nickname describes "Diplopterys cabrerana".


Potamogeton confervoides

Potamogeton confervoides, common names pondweed, alga-like pondweed, algae-like pondweed, and Tuckerman's pondweed is a species of plant found in North America. It is listed as endangered in Connecticut, as a special concern in Maine, as threatened in Massachusetts, New York (state), Pennsylvania, and Wisconsin. It is listed as historical in Rhode Island.


Nacobbus dorsalis

Nacobbus dorsalis (false root-knot nematode) is a plant pathogenic nematode.


Nepenthes viridis

Nepenthes viridis is a tropical pitcher plant endemic to the Philippines. It is known only from coastal areas at low altitude and has been recorded from Dinagat, Samar, and a number of surrounding islets. It is closely allied to the "N. alata" group of species.
The specific epithet "viridis" is Latin for "green" and refers to the plant's typical yellowish-green pitcher colouration, which is maintained irrespective of sun exposure.
Botanical history.
Discovery.
"Nepenthes viridis" was discovered in 2007 by Thomas Gronemeyer and Volker Heinrich. An account of this and other discoveries appeared in a 2008 issue of the German-language periodical, "Das Taublatt", where the plant was treated as a green form of "N. alata".
The recognition of this taxon as a new species—under the placeholder name ""Nepenthes" species 2"—was announced online in September 2012, together with that of four other putative new species from Mindanao and surrounding areas. This followed field work by a team comprising Tobias Gieray, Thomas Gronemeyer, Marius Micheler, David Marwinski, and Andreas Wistuba, though only the last three studied "N. viridis" "in situ" that year.
Formal description.
"Nepenthes viridis" was formally described in a 2013 issue of "Das Taublatt", the magazine of the German carnivorous plant society, Gesellschaft für fleischfressende Pflanzen im deutschsprachigen Raum. Among the six describing authors were Marius Micheler, Thomas Gronemeyer, Andreas Wistuba, and David Marwinski, from Germany, and Wally Suarez and Victor B. Amoroso from the Philippines. The botanical description and subsequent discussion were in German and the diagnosis in English.
The holotype ("CMUH 00008636") was collected by Micheler and Wistuba on 23 August 2012 from Dinagat Island. The specimen is deposited at the Central Mindanao University Herbarium (CMUH), Musuan, Bukidnon, the Philippines.
Prior use of name.
Though this species was only scientifically described in 2013, the binomen "Nepenthes viridis" first appeared in print more than 150 years earlier. Johannes Elias Teijsmann used this name in 1859 to describe a cultivated plant of indeterminate identity, possibly "N. mirabilis". Teijsmann's name is considered a "nomen nudum" (not a validly published name) and was therefore available for describing the present species.
Description.
"Nepenthes viridis" is a climbing plant growing to a height of around 4 m. The stem is roughly circular in cross section and in mature plants reaches 9 mm in diameter, with internodes up to 10 cm long.
Leaves.
Young plants have fimbriate laminae (leaf blades) up to 10 cm long.
Laminae borne on older rosette plants are lanceolate to elliptic and up to 25 cm long by 3.5–4 cm wide. They differ from those of younger plants in lacking fimbriae. One to two longitudinal veins are present on either side of the midrib. The laminar apex is acute. The petiole is canaliculate, semi-amplexicaul, and slightly decurrent down the stem. Tendrils reach 15 cm in length and bear numerous extrafloral nectaries.
The leaves of climbing stems are similar, but are separated by longer internodes. They are long and narrow, sometimes reaching almost three times the pitcher height, at least in plants from Samar.
Pitchers.
In young plants with fimbriate leaves, the pitchers reach 10 cm in height. They have well-developed fringed wings up to 2 mm wide, which run the length of the pitcher cup and bear filaments 2–3 mm long. The peristome is up to 1–2 mm wide. The pitcher lid or operculum is almost perfectly round and reaches 1.5 cm in width. It has a basal keel about 1.5 mm wide.
Rosette and lower pitchers are bulbous in the basal third, becoming cylindrical above and having a slight constriction in the middle. They are up to 16.5 cm high by 4 cm wide. The pitcher opening is up to 3 cm wide. The peristome is cylindrical and up to 5–7 mm wide. The fringed wings are restricted to the upper half of the pitcher cup, the lower parts being reduced to a pair of ribs. The fringe elements are spaced several millimetres apart and the longest (≤1.3 cm) are found in the upper third of the pitcher, near the peristome. The lid is round to slightly cordate (heart-shaped). It is distinctly domed and has a diameter of up to 3.5 cm. On the underside of the lid, the basal keel is 7–8 mm long and 3 mm high. A branched spur 2–3 mm long is inserted near the base of the lid.
Upper pitchers are ovoid in the basal third and cylindrical above, expanding rapidly just below the peristome. They are similar in size to their terrestrial counterparts, reaching 18 cm in length by 2.4 cm in width. The peristome is cylindrical to slightly flattened and around 5 mm wide. It is often raised at the front, where it is notched or wavy. The pitcher opening is up to 3.6 cm in diameter. The wings are reduced to ribs and lack filaments altogether. The lid is oval to cordate and, as in lower pitchers, heavily domed. It measures around 3.8 by 3.2 cm and has a basal keel on its lower surface. The keel is similarly sized to that of lower pitchers: 7–8 mm long by 3 mm high. The spur is up to 4 mm long.
In the wild, both lower and upper pitchers are predominantly yellowish-green, even when growing exposed to direct sunlight, though in some plants the wing vestiges of the upper pitchers may be slightly reddish. The inner surface visible through the pitcher opening is near-white.
Inflorescence.
"Nepenthes viridis" has a racemose inflorescence up to 60 cm long, of which the rachis (the flower-bearing portion) constitutes up to 50 cm, the remainder being a short peduncle. The flowers are mostly borne on two-flowered partial peduncles, which are up to 2.5 cm long.
Ecology.
Distribution and habitat.
"Nepenthes viridis" is endemic to the Philippines. It has been recorded from coastal areas of Dinagat and Samar, and from a number of surrounding micro-islands. Plants generally grow terrestrially on humic and rocky soils, often in direct sunlight.
The tiny islets this species inhabits around Dinagat provide striking micro-habitats, often having near-vertical rock walls and highly vegetated tops. Here, "N. viridis" plants occasionally grow lithophytically, their roots anchored in fissures. Where present, surrounding vegetation provides support for the plants' scrambling vines, though these may overhang the sheer rock faces, dangling only a few metres from the water. Exposed to direct sunlight, the dark rock walls can get very hot, and during particularly dry periods any "N. viridis" plants in close proximity will largely wither, leaving only a few green shoots.
Natural hybrids.
No natural hybrids involving "N. viridis" have been documented with certainty. Although Dinagat hosts five other "Nepenthes" species ("N. bellii", "N. merrilliana", "N. mindanaoensis", "N. mirabilis", and "N. truncata"), these are found in more inland areas and none are known to grow alongside "N. viridis". Crosses with "N. viridis" are more likely to occur on Samar, where the species is sympatric with "N. merrilliana" and "N. alata" "s.l.".
Related species.
"Nepenthes viridis" is closely allied to the "N. alata" group of species, which includes "N. alata", "N. ceciliae", "N. copelandii", "N. extincta", "N. graciliflora", "N. hamiguitanensis", "N. kitanglad", "N. kurata", "N. leyte", "N. mindanaoensis", "N. negros", "N. ramos", "N. saranganiensis", and "N. ultra". These species are all endemic to the Philippines and are united by a number of morphological characters, including winged petioles, lids with basal ridges on the lower surface (often elaborated into appendages), and upper pitchers that are usually broadest near the base.
Taxonomy of "N. alata" group.
Shortly before the "N. viridis" type description went to print, botanists Martin Cheek and Matthew Jebb published a series of papers splitting "N. alata" "sensu lato" into several daughter taxa, including the newly delimited "N. alata" "sensu stricto" (restricted to northern Luzon), the newly resurrected "N. graciliflora" (Bohol, Leyte, Luzon, Mindanao, Mindoro, Panay, Samar, and Sibuyan), as well as the newly described "N. negros" (Biliran and Negros) and "N. ramos" (Mindanao). Under this new classification, most populations previously regarded as "N. alata" now fall under "N. graciliflora". Though the "N. viridis" type description made mention of these taxonomic changes, the authors noted that Cheek and Jebb's determinations were based solely on herbarium material and did not involve field research. Moreover, they noted that the status of the ""N. alata" group" in Mindanao remained unclear, since both "N. alata" and "N. graciliflora" usually have flowers borne singly on pedicels, whereas populations with two-flowered partial peduncles are known from Mindanao. They added that the description of "N. ramos" (a species from Mindanao with two-flowered partial peduncles) did not resolve the situation, as the lower pitchers of this species remained unknown. For these reasons the authors decided to compare "N. viridis" not against "N. alata" "s.s." as defined by Cheek and Jebb, but against "N. alata" "s.l." as described in B. H. Danser's 1928 monograph, "The Nepenthaceae of the Netherlands Indies", and later refined in Stewart McPherson's 2009 work, "Pitcher Plants of the Old World".
Comparison to "N. alata".
"Nepenthes viridis" is distinct from "N. alata" "s.l." in several aspects of pitcher morphology. Most obviously, the upper pitchers are much narrower, becoming particularly constricted in their upper third, before widening rapidly just below the peristome. This is in contrast to "N. alata", in which the upper pitchers are more-or-less cylindrical and not nearly as constricted. In "N. viridis" the front portion of the peristome is raised and crenellated; such a structure is not found in "N. alata". The pitcher lid of "N. viridis" is also distinctive, being heavily domed and having a prominent keel or keeled appendage on the basal midline of the lower surface. "Nepenthes alata", by contrast, usually bears a triangular appendage or reduced keel, and does not have a domed lid. There are also notable differences in the development of the ventral pitcher wings. Those of "N. viridis" lower and intermediate pitchers are restricted to the upper third of the pitcher cup and bear large (≤13 mm), widely spaced filaments. By comparison, those of "N. alata" intermediate pitchers usually run the length of the pitcher cup with more densely arranged filaments (2–4 mm apart). The small spur located near the base of the lid is another distinguishing feature. In lower pitchers of "N. viridis" it is branched, whereas in "N. alata" it is not.


Pittosporum eugenioides

Pittosporum eugenioides, common names lemonwood or tarata, is a species of New Zealand native evergreen tree. Growing to tall by broad, it is conical when young but more rounded in shape when mature. Its leaves are mottled yellow-green with curly edges and a salient bright midrib, and have a strong lemony smell when crushed. It has highly fragrant clusters of attractive yellow-cream flowers in spring, followed by distinctive black seed capsules. It is found throughout New Zealand's North and South Islands along forest margins and stream banks from sea level to . It is New Zealand's largest "Pittosporum".
The binomial qualifier "eugenioides" means "resembling "Eugenia"", a different genus of plants.
The variegated cultivar 'Variegatum' has gained the Royal Horticultural Society's Award of Garden Merit.
Life cycle/phenology.
Pittosporum eugenioides starts out as a small compact tree, as it matures it becomes a tall branched tree. The lemonwood flowers between October and December. The following year after flowering the capsules will open. The capsules open the next year because the fruit of the lemonwood takes between 12 and 14 months to ripen. There is unripe fruit and ripe fruit present on the lemonwood at the same time, this is the current season’s fruit and last season’s fruit. Lemonwood is pollinated by both insects and birds, the seeds are bird dispersed. The seeds of the lemonwood germinate quickly and will become seedlings within a month.
Range.
"Pittosporum euegnioides" is endemic to New Zealand. There are “about 200 trees and shrubs” in the genus located in neighbouring parts of the world. Countries with the same genus found include; Africa, Australia, some Pacific islands, southern & eastern Asia, and New Zealand.
A reason for this endemic occurrence is due to the isolation of New Zealand over a long period of time.
New Zealand range.
"Pittosporum euginiodes" is found throughout New Zealand’s South Island and North Island in low lying forests. It is found in forest clearings and along forest margins up to 600m above sea level.
Habitat preferences.
"Pittosporum euegnioides" can be found in a cooler, mature, lowland and subalpine forest climate zone throughout New Zealand. The species can be found in regenerating areas of forest, both young and old. It has proved to be a great plant for establishing a quick canopy.
This species, along with other "Pittosporum" are making their way in to the average house hold garden’s. Nurseries and Garden Centre’s are stocking this native because it is suited to New Zealand conditions where it naturally grew many years ago.
At home in the garden, "P. euegnioides" prefers a sunny to part shade position, does not mind the wind, and thrives in soil with good drainage.
Cultivation.
The viability of the lemonwood's seeds is affected by moisture levels of the soil. If the moisture levels are too high the seed is likely to become unviable. The lemonwood like other pittosporums is somewhat drought resistant therefore rainfall is not a major factor in the lemonwoods survival. P. eugenioides is relatively simple to look after from season at home. It grows well, thriving off regular watering intervals during Summer. It enjoys a feed with general tree and shrub fertiliser twice a year during Spring and Summer while it is growing. Responds well to pruning also, which will assure survival in the forest too if disturbed.
Ecology.
The pittosporum flower weevil ("Aneuma rubricale") is a parasite that feeds on the underside of the lemonwood leaves. This parasite does not kill the lemonwood it just damages the leaves through its feeding. The holes the weevils eat in the leaves are visible because the leaf reacts causing a dark brownie purple ring to form around the hole. Pittosporum eugenioides is only a host to the adult weevil as the larvae are hosted on different pittosporums. Common garden pests can cover this plant, such as Aphids and blister scale (Psyilids). Both can easily be controlled and treated with an insecticide. The best time to spray as a preventative is February, then again in October.
Citrus aroma.
The sweet scent of the flowers suggest nectar loving birds find this an ideal plant to forage from. The experiment was carried out to see if the citrus-like chemicals were the same ones that are present in lemon-like species, such as Verbena varieties. The lemony leaves are a unique combination of scented chemicals found in the oil produced. Octyl acetae, Terpinen-4-ol and Decanol were found in a test that was carried out. Octyl acetae is responsible for the “fruity, Jasmine, herbaceous aroma”. Terpinen-4-ol scent is “somewhere between peppermint and pine”. Finally, Decanol is a "fatty, orange blossom odor". Results of this test unearthed that this lemonwood aroma combination is very unusual for this genus and the chemicals are different to what you would find in other citrus scented species.
Traditional uses.
Cultural uses.
Maori traditionally used the gum and crushed leaves and flowers of the tarata for scent, usually mixed with plant oils such as titoki and kohia.
Maori also used the lemonwood to make hair oils and perfume. For perfume, the oil was mixed with bird fat. The gum from the tree was used for bad breath. They rolled the gum in to a ball and this was thought to last a whole generation. The gum made a great glue when chewed as well.
Restoration planting.
"Pittosporum eugenioides" is great for establishing a shade canopy in a restoration setting. It then provides an opportunity to introduce understory, shade loving plants to the same location, later planting underneath the lemonwood trees. It is recommended to plant this species closer than you would normally find in the established forest. “close planting imitates the growth of the seedlings on the forest floor”, resulting in plants tending to grow upward more rapidly. "P. eugenioides" is one of the best plants for this rapid canopy growth because it is already fast growing.
Lemonwood is on the recommended list for replanting “small trees up to 6m” naturally occurring species in to the design guidelines of the Christchurch City Council. “Hardy native species offer a great number of benefits” and are more flexible to suit local conditions compared to “foreign” plant selection.
Home garden design.
It is important to include historic, naturally occurring species planting design because they perform well in local conditions. “As well as looking good, the design provides wildlife habitat, recreational spaces, also assisting in filtering water runoff”.
"P. eugenioides" in a home setting will most likely be found as a hedging or screening plant. Happy to be near a swimming pool, a great choice too because it has minimal leaf litter drop. Great in a windy position in a design and also provides a barrier for the surrounding more intolerant plants. Great as a greenery backdrop with the textural leaves clustered together as well.


Phyllospadix juzepczukii

Phyllospadix juzepczukii is a plant species known only from shores of the Russian Far East (Sakhalin, Khabarovsk and Primorye). It grows in salt marshes along the intertidal zones of the Sea of Okhotsk.