Citation {#SECID0EEAAC}
========

Surveswaran S, Kumar P, Sun M (2017) *Spiranthes himalayensis* (Orchidaceae, Orchidoideae) a new species from Asia. PhytoKeys 89: 115--128. [https://doi.org/10.3897/phytokeys.89.19978](10.3897/phytokeys.89.19978)

Introduction {#SECID0EEBAC}
============

*Spiranthes* [@B16]:28) is a genus of terrestrial herbs belonging to the family Orchidaceae, comprising about 36 species, four varieties and four natural hybrids ([@B6]). The genus is widely distributed from Eurasia to Southwest Pacific, North Africa, North and Central America to the Caribbean ([@B6]). Of these, around seven species are found in Asia, including three in China and two in India ([@B3], [@B20], [@B6]).

While sampling *Spiranthes* in an aim to study the evolution and phylogeography of the genus in Asia, a white-flowered pubescent *Spiranthes* was discovered, which, based on DNA studies, was found to be distinct with respect to other known *Spiranthes* species (Fig. [1](#F1){ref-type="fig"}). It showed close affinity to *S. nivea* T.P Lin & W.M. Lin ([@B11]) which is endemic to Taiwan (Fig. [1](#F1){ref-type="fig"}). It was also proven not to be *S. sinensis* (Pers.) Ames or *S. spiralis* (L.) Chevall. which are commonly distributed in Asia and Europe respectively (Fig. [1](#F1){ref-type="fig"}). Based on both morphological and genetic data, this white-flowered pubescent species is hitherto considered to be a new species that had formerly been misidentified as *S. sinensis*, *S. spiralis* or *S. hongkongensis* S.Y. Hu & Barretto in India and China (see Taxonomic notes). Based on sampling in southern India, North East India and South China, this species is now known to be widely distributed. Considering this as a new species, its morphological synapomorphies are enumerated here. Morphological comparisons have also been provided with allied species, *S. sinensis*, *S. hongkongensis* and *S. nivea*.

![Bayesian phylogenetic tree indicating *Spiranthes himalayensis* Survesw., Kumar & Mei Sun sp. nov. Sequences generated for this study are indicated in bold, specimen identification numbers and area of collection are indicated beside the species names. Bayesian probability supports are indicated at the nodes.](phytokeys-89-115-g001){#F1}

Methods {#SECID0EXHAC}
=======

Morphological observations of the new species were carried out based on living plants as well as dry specimens. Measurements were made using a ruler and a micrometer. Both herbarium and fresh specimens were examined under a stereo dissecting microscope and photographs were taken with a Nikon SMZ16 stereomicroscope connected to a digital camera.

A combined dataset of nuclear ITS, chloroplast *trnL-trnLF* intron/intergenic spacer, *trnS-trnG* intergenic spacer and maturase K (*matK*) sequences were used for the analysis (Table [1](#T1){ref-type="table"}). The sequences were generated using primers described in [@B5]. Molecular phylogenetic analysis was performed using MrBayes version 3.2.6 ([@B17]). One million generations of MCMC chains were run in MrBayes implementing the GTR+I+G model. Independent analysis of the nuclear and plastid markers were congruent and the combined analysis is presented here.

###### 

Genbank accession numbers of sequences used.

  ----------------------------- ---------------- ---------------------- ---------------------- ---------------------- ----------------------
  Name                          Specimen id      ITS                    *trnL*                 *trnSG*                *matK*
  *Spiranthes sinensis*         S5               [MF286487](MF286487)   [MF286400](MF286400)   [MF286356](MF286356)   [MF286445](MF286445)
  *S. sinensis*                 S17              [MF286496](MF286496)   [MF286411](MF286411)   [MF286367](MF286367)   [MF286455](MF286455)
  *S. sinensis*                 S15              [MF286494](MF286494)   [MF286409](MF286409)   [MF286365](MF286365)   [MF286453](MF286453)
  *S. sinensis*                 S12              [MF286493](MF286493)   [MF286406](MF286406)   [MF286362](MF286362)   [MF286450](MF286450)
  *S. sinensis*                 Si17             [KM262400](KM262400)   [KM283611](KM283611)   [KM283585](KM283585)   [KM262488](KM262488)
  *S. himalayensis*             C1 (HJCB 0442)   [MF286478](MF286478)   [MF286389](MF286389)   [MF286343](MF286343)   [MF286432](MF286432)
  *S. himalayensis*             M1 (HJCB 1001)   [MF286481](MF286481)   [MF286391](MF286391)   [MF286346](MF286346)   [MF286435](MF286435)
  *S. himalayensis*             S52              [MF286511](MF286511)   [MF286430](MF286430)   [MF286387](MF286387)   [MF286475](MF286475)
  *S. nivea*                    S9               [MF286490](MF286490)   [MF286403](MF286403)   [MF286359](MF286359)   [MF286448](MF286448)
  *S. nivea*                    S10              [MF286491](MF286491)   [MF286404](MF286404)   [MF286360](MF286360)   [MF286449](MF286449)
  *S. spiralis*                 Sp51             [KM262410](KM262410)   [KM283619](KM283619)   [KM283595](KM283595)   [KM262490](KM262490)
  *S. aestivalis*               Sa59             [KM262409](KM262409)   [KM283621](KM283621)   [KM283594](KM283594)   [KM262492](KM262492)
  *S. parksii*                  20a              [EU384861](EU384861)   [EU384800](EU384800)   [EU384739](EU384739)   [KM262231](KM262231)
  *S. cernua*                   04v              [KM262285](KM262285)   [KM283636](KM283636)   [KM283448](KM283448)   [KM213798](KM213798)
  *S. ochroleuca*               16a              [KM262322](KM262322)   [KM283680](KM283680)   [KM283492](KM283492)   [KM213844](KM213844)
  *S. magnicamporum*            15f              [KM262320](KM262320)   [KM283678](KM283678)   [KM283490](KM283490)   [KM213843](KM213843)
  *S. lacinata*                 12e              [KM262315](KM262315)   [KM283672](KM283672)   [KM283484](KM283484)   [KM213829](KM213829)
  *S. tuberosa*                 26c              [KM262384](KM262384)   [KM283623](KM283623)   [KM283568](KM283568)   [KM262466](KM262466)
  *S. sylvatica*                25d              [EU384871](EU384871)   [EU384819](EU384819)   [EU384759](EU384759)   [KM262464](KM262464)
  *S. praecox*                  22f              [KM262363](KM262363)   [KM283733](KM283733)   [KM283545](KM283545)   [KM262438](KM262438)
  *S. romanzoffiana*            24f              [KM262371](KM262371)   [KM283741](KM283741)   [KM283553](KM283553)   [KM262447](KM262447)
  *S. deliticens*               05a              [KM283646](KM283646)   [KM283646](KM283646)   [KM283458](KM283458)   [KM213774](KM213774)
  *S. diluvialis*               06a1             [KM262298](KM262298)   [KM283649](KM283649)   [KM283461](KM283461)   [KM213777](KM213777)
  *Dichromanthus aurantiacus*   --               [AJ539485](AJ539485)   [AJ544468](AJ544468)   --                     [AJ543913](AJ543913)
  *Mesadenus polyantha*         --               [KU752294](KU752294)   [KU740269](KU740269)   --                     [AJ543916](AJ543916)
  ----------------------------- ---------------- ---------------------- ---------------------- ---------------------- ----------------------

Taxonomy {#SECID0EFSAE}
========

Spiranthes himalayensis
-----------------------

Plantae

Asparagales

Orchidaceae

Survesw., Kumar & Mei Sun sp. nov.

urn:lsid:ipni.org:names:77167300-1

[Figs 2B](#F2){ref-type="fig"} [, 2C](#F2){ref-type="fig"} [, 3](#F3){ref-type="fig"} [, 4A](#F4){ref-type="fig"}

### Type.

INDIA. Manipur: Ukrul district, Imphal-Jessami road, found on a paddy field on the way to Ukhrul town from Imphal, 1 May 2016. *S. Surveswaran 1* (*HJCB 1001*) (holotype JCB!) (specimen id M1 in DNA based phylogeny, Fig. [1](#F1){ref-type="fig"}).

### Diagnosis.

*Spiranthes himalayensis* Survesw., Kumar & Mei Sun *sp. nov*. is similar to *S. hongkongensis*, *S. nivea* and *S. sinensis*, but can be differentiated on the basis of its allogamous mode of reproduction from *S. hongkongensis* and *S. nivea* which are both autogamous. It can also be easily separated from *S. nivea* by its pubescent body. Other morphological distinctions separating this new species from *S. hongkongensis*, *S. nivea* and allogamous *S. sinensis* include: floral bract longer or of the same length as the ovary, petals with blunt apex, labellum width around hypochile is same as the width of epichile, epichile widely flabellate or semi-tunicate, column length equal to or more than 1.5 mm, clavate operculum attached to the column on the broader part by an arm-like extension emerging from the upper part of column and a well-developed rostellum separating the stigma from the pollinarium.

### Description.

Terrestrial herbs with perennating rhizome. Plants c. 16--30 cm tall. Rhizome about 3mm in diameter. Stem erect, leaf clustered towards the base. Leaves 2 to 5 per plant, broadly linear or linear-lanceolate, 4.0--6.0 cm long, ca. 1.5cm wide, 3-veined with depression on upper surface and elevated lining underneath, spreading from the base of the stem. Inflorescence tall, up to 30 cm long, terete, pubescent, covered with glandular hairs, with 1--3 sterile bracts sheathing the peduncle, flowers spirally arranged, clustered towards the upper one-fourth of the peduncle with flowers opening from the base. Flowers widely open 0.22 × 0.26 cm wide, 0.43 cm long, pale white to pale butter-white, pubescent with glandular hairs. Bracts green, equal to or longer than the combined length of pedicel and ovary, ovate-lanceolate, 0.40--0.50 cm long, ca. 0.17 cm wide, acuminate, hairy on the outer surface, sheathing the base of flower, margin white. Dorsal sepal white, hairy towards the base, elongated-triangular, 0.35--0.40 cm long, ca. 0.10 cm wide, obtuse. Lateral sepals white, pubescent towards the base, obliquely elliptic, 0.37--0.40 cm long, 0.10 cm wide, obtuse. Petals white, pubescent towards the base, obliquely elliptic, ca. 0.37 cm long, ca. 0.07 cm wide towards the base, 0.09 cm wide towards apex, apex blunt. Labellum white, distinctly divided into hypochile and epichile with a constriction in the middle, hairy on the outer surface, ca. 0.50 cm long; hypochile concave, ca. 0.30 cm long, 0.33--0.34 cm wide, attached at the base of short foot below the column, saccate, sac 0.05 cm deep, with one semi-globular gland on each side (0.05 cm wide, 0.04 cm high), margin entire and raised upwards till the constriction; epichile semi-tunicate, flabellate, ca. 0.20 cm long, ca. 0.30 cm wide, margin undulate, slightly dentate with some papillose hairs on the front semi-tunicate part. Column green-white, obconical, quadrangular transversely quandrangular, 0.25 cm long, 0.05 cm at the base, 0.07 cm wide towards the apex, with a short foot at the base, 0.06 cm long, stigma at the apex on the lower side, green in colour, shiny, filled with viscid liquid, trapezoid shaped, broad towards base (0.08 cm), narrower towards apex (0.06 cm), 0.06 cm long. Rostellum well developed with two semi-transparent, clavate, rostellar arms projecting in the front above stigma, 0.06 cm long. Pollinarium yellow, ovate with a deep cleft, 0.22 cm long, 0.09 cm wide, narrower end at the apex while the lobes inside covered with operculum, with a ligulate viscidium at the narrower end, 0.1 cm long. Operculum yellow-brown coloured, partly embedded on the upper part of column, not free, convex, ca. 0.10 cm long, 0.06 cm wide. Ovary sessile or with inconspicuous pedicel, densely haired, fusiform, 0.20--0.25 cm long, 0.11--0.13 cm wide. Fruits obliquely clavate, ca. 0.30 cm long, 0.12 cm wide, densely pubescent with glandular hairs.

### Phenology.

Flowering: March--June. Fruiting: March--July.

### Habitat.

Marshy areas near mountain streams or on bunds of paddy fields (Fig. [2A](#F2){ref-type="fig"}) where water is stagnant. Plants were usually found growing on clayey soil along with grasses.

![Habitat and habit of *Spiranthes himalayensis* Survesw., Kumar & Mei Sun, sp. nov. **A** Habitat (type location) - along the bunds of paddy fields **B** Habit of *S. himalayensis* **C** Close-up of the inflorescence showing white coloured flowers with densely covered glandular hairs.](phytokeys-89-115-g002){#F2}

### Etymology.

The specific name refers to the mighty Himalayan mountain range which is an important geographical feature in Asia. The samples collected for this study were not from the Himalayas. However, based on herbarium records and communication with other researchers, it is believed that this species is widespread in the lower altitudes of Himalayas. The evolutionary origin of this species and other Asian *Spiranthes* are to be further elucidated.

### Currently known locations of distribution.

India (Karnataka, Manipur & Tamil Nadu) & China (Yunnan and most likely Hainan (see taxonomic notes for details)).

### Conservation status.

Based on DNA analysis, the occurrence of *Spiranthes himalayensis* can be confirmed in India and China. This species is likely to be present in a much wider geographic range where it has long been misidentified (see taxonomic notes). It was not possible to assess the specimens which might have been misidentified as *S. sinensis* or *S. spiralis* across its broad distributional range. It is emphasised that the type specimen was collected in an agricultural field and other specimens were found on roadsides along mountain slopes above 1000 m in its wide distributional range. Therefore it is speculated that this species might be of least concern for conservation. However large-scale habitat loss and fragmentation of habitats in Asia might pose a threat to this species. Since a thorough assessment has not been undertaken, the conservation status of Not Evaluated (NE) has been assigned to this species as per IUCN Red List categories and criteria (2017).

### Other specimens examined.

INDIA. Manipur: Ukrul district, Imphal-Jessami Road, found on paddy fields on the way to Ukhrul town, 1200 m, 1 May 2016, *S. Surveswaran 1HJCB 1001* (M1-DNA specimen) (JCB); Karnataka: Chickmagalur district, near Kemmankundi, 1400 m, 14 June 2015, *S. Surveswaran 4* (*HJCB 0442*) (C1-DNA specimen) (JCB!); Tamil Nadu: Coimbatore, near Konalar anti-poaching protection camp, Grass Hills, Valparai Range, Anaimalai Tiger Reserve, 1200 m, 13 March 2012, *K. Ravikumar & A.C. Tangavelou FRLH-121312* (FRLH!). CHINA. Yunnan Province: Malipo County, Wenshan, near Xiajinchang village, 1400 m, 20 May 2016, *S. Surveswaran S52*.

![*Spiranthes himalayensis* Survesw., Kumar & Mei Sun, sp. nov. **A** Complete plant **B** Inflorescence **C** Floral bract **D** Dorsal sepal **E** Lateral sepal **F** Petal **G** Ovary with column and labellum **H** Close-up showing the glandular hairs on flower and ovary **I** Side view of labellum **J** Top view of labellum **K** Side view of ovary with column **L** Front view of ovary and column **M** Front view of pollinarium **N** Side view of pollinarium. Note: The pinkish/bluish hue on petals of *S. himalayensis* is due to the black background in the plates while the flowers appear fully white in natural light.](phytokeys-89-115-g003){#F3}

![Comparison of morphological characters of allied species. **A***Spiranthes himalayensis*: **1** Close-up of inflorescence **2** A flower **3** Floral bract **4** Dorsal sepal **5** Lateral sepal **6** Petal **7** Ovary with column and labellum **8** Labellum (side view) **9** Labellum (top view) **10** Close-up showing glandular hairs on labellum and ovary **11** Ovary with column (side view) **12** Ovary with column (ventral view) **B***S. sinensis*: **1** Close-up of inflorescence **2** A flower **3** Floral bract **4** Dorsal sepal **5** Lateral sepal **6** Petal **7** Ovary with column and labellum **8** Labellum (side view) **9** Labellum (top view) **10** Ovary with column (side view) **11** Ovary with column (ventral view) **C***S. hongkongensis*: **1** Close-up of inflorescence **2** A flower **3** Floral bract **4** Dorsal sepal **5** Lateral sepal **6** Petal **7** Ovary with column and labellum; 8. Labellum (side view) **9** Labellum (top view) **10** Close-up showing glandular hairs on labellum and ovary **11** Ovary with column (side view) **12** Ovary with column (ventral view) **D***S. nivea*: 1. Close-up of inflorescence; 2. A flower **3** Floral bract **4** Dorsal sepal **5** Lateral sepal **6** Petal **7** Ovary with column and labellum **8** Labellum (side view) **9** Labellum (top view) **10** Close-up showing glandular hairs on labellum and ovary **11** Ovary with column (side view) **12** Ovary with column (ventral view). Note: The pinkish/bluish hue on petals of *S. himalayensis*, *S. nivea* and *S. hongkongensis* is due to the black background in the plates while the flowers appear fully white in natural light.](phytokeys-89-115-g004){#F4}

### Note.

Hairy *Spiranthes* have been reported very often from India, sometimes under the name of *S. sinensis* ([@B10], [@B12]) and, at other times, under the name of *S. spiralis* ([@B4], [@B13]). [@B7] also described two species of *Spiranthes*, *S. australis* (= *S. sinensis*) and *S. autumnalis* (= *S. spiralis*) from India. As the protologue of *S. sinensis* does not mention the presence or absence of hairs ([@B14]), there has been no clear distinction between *S. sinensis* and the new white flowered *S. himalayensis* amongst the various reports. So far, a true *S. spiralis* has not been found in India and the specimens treated as *S. spiralis* might have been *S. himalayensis* sp. nov. In this study, it was out of the scope to trace all specimens or vouchers of hairy *Spiranthes* and distinguish them from *S. sinensis* which could also be hairy in some natural populations.

[@B18] reported *Spiranthes sinensis* from Thailand, illustrating a hairy plant with long and stalked glands in the hypochile. This specimen is also suspected to be the new species *S. himalayensis* described here. [@B4] reported *S. sinensis* and *S. spiralis* from northwest Himalaya, differentiating them on the basis of multiple roots; elongated, fleshy, cylindrical tubers; lanceolate leaves, present during flowering and pink flowers in the former against 2--3 roots; fleshy carrot shaped tuber; ovate leaves, absent during flowering; white or greenish-white flowers in the latter. They also illustrated *S. sinensis* with hairy flowers and well developed rostellum with two rostellar arms. For *S. spiralis*, they just gave an illustration of tubers, but we believe that this sample could also be the new species described here. They also mentioned that *S. sinensis* was found in two colours, pink and white. This could be the source of confusion leading to the misidentification of our new species as *S. sinensis* by other workers. [@B10] reported *S. sinensis* from Kerala, South India, stating that it is a variable species but no description was provided. Pink flowered forms of *Spiranthes* have not been observed in southern India, indicating an absence of the true *S. sinensis* in this area and the white flowered species reported as *S. sinensis* is also most likely to be the new species, *S. himalayensis*, described here. [@B1] recently described a new record of *S. spiralis* from Pokhara valley in Nepal with glandular hairs and a flowering season similar to *S. himalayensis*. It is suspected that this plant from Nepal could also be *S. himalayensis* sp. nov. but it was not possible to acquire the specimen for detailed morphological or DNA study. The morphological description in this publication would help with the correct identification of the new species, *S. himalayensis* in the future.

[@B15] (fig. 203.1) illustrated *Spiranthes sinensis* based on *Pantling 107* (K) and *Grierson & Long 3986* (K), showing hairy plants looking very similar to *S. himalayensis* sp. nov. However, the flower colour cannot be confirmed from the line drawings.

[@B8] reported the presence of a species of *Spiranthes* at an altitude of about 800 m on a grassy slope of Diaoluoshan of Hainan Island, China, which they revised as *S. hongkongensis* from a previous misidentification as *S. sinensis.* However, based on the plant picture presented in Hainan Rainforest Exhibition Hall, the Hainan species looks like the new species *S. himalayensis* (based on floral morphology and lack of fruit set at the base of inflorescence, personal observations). Therefore it is likely that *S. himalayensis* might be extending its range up to Hainan Island. Genetic evidence of the occurrence of *S. himalayensis* in China has been obtained from a population located in Yunnan where at least two plants were consistently placed in the species clade of *S. himalayensis* whether nuclear ITS or chloroplast DNA was used in the data analysis (Surveswaran and Sun, unpublished).

Based on DNA studies (Fig. [1](#F1){ref-type="fig"}), the samples of *Spiranthes himalayensis* formed a distinct species clade, sister to *S. nivea* clade. Both *S. himalayensis* and *S. nivea* are distinct from *S. sinensis* which forms a large monophyletic clade including samples from a wide geographical range such as Hong Kong, Taiwan and mainland China, Korea, Japan, Australia and New Zealand. It should be noted that *S. sinensis* is highly polymorphic in flower colour, varying from purple pink to white and also in the extent of hairiness, from glandular to glabrous. The distinguishing morphological features of *S. sinensis* include: floral bract equal to or longer than the length of ovary, petals with rounded apex, labellum width around hypochile is half of the width of epichile, epichile widely semi-tunicate, column length less than 0.5 mm long, upper part of operculum attached to column with the arm emerging from the top of column, well developed rostellum partitioning the stigma and pollinarium. On the other hand, *S. hongkongensis* always has white flowers with occasionally pinkish tint on the petal and glandular hairs on various parts of the plant, but its floral bract is equal to or shorter than the length of ovary, petals have rounded apex, labellum width around hypochile is equal or slightly greater than the width of epichile, epichile not tunicate, column length up to 1mm long, lower half of operculum embedded on to column, rostellum absent and pollinia lying directly above stigma rendering autogamy. In contrast, *S. nivea* has short papillose hairs inconspicuous to the naked eye, flower colour is always white without pinkish tint, floral bracts are much longer than the length of ovary, petals have a blunt apex, labellum width around hypochile being more than the width at epichile, epichile not being tunicate, column length almost 0.5 mm, lower half of operculum embedded in the column, rostellum absent and pollinia lying directly above stigma rendering autogamy (see Table [2](#T2){ref-type="table"}).

###### 

Comparison of morphological characters of *Spiranthes himalayensis* Survesw., Kumar & Mei Sun, sp. nov., *S. sinensis*, *S. hongkongensis* and *S. nivea.*

  ------------------------------------ --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
  Character                            *Spiranthes himalayensis*                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 *Spiranthes sinensis*                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               *Spiranthes hongkongensis*                                                                                                                                                                                                                                                                                                                                                                                     *Spiranthes nivea*

  **Flowering time**                   March to June                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             April to June (in Hong Kong), August to September (in India)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        March to early June                                                                                                                                                                                                                                                                                                                                                                                            April to June

  **Inflorescence**                    Pubescent with glandular hairs                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            Pubescent or sometimes glabrous                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     Pubescent with glandular hairs                                                                                                                                                                                                                                                                                                                                                                                 Glabrous, but with microscopic non-glandular papillose hairs

  **Flower**                           White, pale white, widely open, 0.4--0.5 × 0.15 cm wide, ca. 0.43 cm long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 Pink, or purple, but occasionally white, widely open, 0.19 × 0.22 cm wide, ca. 0.45 cm long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         White, petals and sepals rarely pink tinged, labellum white, widely open, 0.10, 0.12 cm wide, ca. 0.38 cm long                                                                                                                                                                                                                                                                                                 White, tubular on lower 2/3rd, open towards the tip, 0.09 × 0.09 cm wide, ca. 0.41 cm long

  **Bract**                            Equal to or longer than ovary, 0.4--0.5 cm long, ca. 0.17 cm wide                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         Equal to or longer than ovary, 0.36 cm long, 0.14 cm wide                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           Equal to or shorter than ovary, ca. 0.37 cm long, 0.19 cm wide                                                                                                                                                                                                                                                                                                                                                 Much longer than ovary arching over the flower, 0.49 cm long, 0.16 cm wide

  **Petal**                            Apex blunt                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                Apex rounded                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        Apex rounded                                                                                                                                                                                                                                                                                                                                                                                                   Apex blunt

  **Labellum**                         Labellum white, pubescent on the outer surface, distinctly divided into hypochile and epichile with a constriction in the middle, ca. 0. cm long; hypochile ovate, concave or saccate, ca. 0.30 cm long, 0.33--0.34 cm wide, sac 0.05 cm deep, with a pair of semi-globular gland at the base (0.05 cm wide, 0.04 cm high), margin entire and raised upwards till the constriction, two broad pale green patch at the constriction; epichile semi-tunicate, flabellate, ca. 0.20 cm long, ca. 0.30 cm wide, margin undulate, slightly dentate with some papillose hairs on the front semi-tunicate part   Labellum pink or white, glabrous, not distinct into epichile and hypochile due to lack of constriction, rather a semi-cylindrical basal portion with tunicate or flabellate frontal portion, 0.46 cm long; basal portion 0.15 cm wide, 0.23 cm long, saccate, sac 0.03 cm deep, margin raised with a pair of semi-globular glands at the base (0.05 cm wide, 0.05 cm high), margin smooth towards base, undulate from almost middle of the basal portion to the whole length of frontal portion; frontal portion semi-tunicate or flabellate, 0.13cm long, 0.16 cm wide at base, 0.35 cm wide towards the apex, margin undulate, slightly dentate   Labellum white with rare pinkish tinge, distinctly divided into hypochile and epichile with a constriction in the middle,\                                                                                                                                                                                                                                                                                     Labellum white, glabrous, not distinct into epichile and hypochile due to lack of constriction, rather a semi-conical basal portion with semi-cylindric frontal portion, 0.43cm long; basal portion 0.24 cm wide towards base, 0.14 cm wide towards upper part, 0.24 cm long, saccate, sac 0.03 cm deep, margin raised with a pair of semi- globose glands at the base (0.04 cm wide, 0.04 cm high), margin smooth till the base of frontal part of labellum; frontal portion not widely spreading, margin convolute, 0.19 cm long, 0.16 cm wide at base, 0.14 cm wide towards the apex, margin undulate towards base and slightly dentate towards apex
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     ca. 0.58 cm long; hypochile ovate, slightly concave or saccate, 0.26 cm long, 0.32 cm wide, 0.06 cm deep, with a pair of trapezoidal shaped gland at the base (0.09 cm wide, 0.07 cm high), margin entire and raised upwards till the constriction; no colour patch at the constriction; epichile semi-tunicate, flabellate, ca. 0.26 cm long, ca. 0.26 cm wide, margin undulate, slightly dentate, glabrous   

  **Labellum apex**                    Recurved, \> 270 degrees                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  Strongly recurved, almost 360 degrees                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               Recurved by \< 270 degrees                                                                                                                                                                                                                                                                                                                                                                                     Recurved by \< 270 degrees

  **Column**                           Column, obconical, 0.25 cm long, 0.05 cm at the base, 0.07 cm wide towards the apex; foot 0.06 cm long; stigma trapezoid shaped, broad towards base (0.08 cm), narrower towards apex (0.06 cm), 0.06 cm long.                                                                                                                                                                                                                                                                                                                                                                                             Column conical, 0.23 cm long, 0.08 cm wide at the base, 0.10 cm wide at the apex; foot 0.05 cm long; stigma almost semicircular in shape, 0.09 cm wide                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              Column, obconical, 0.21 cm long, 0.07 cm at the base, 0.09 cm wide towards the apex; foot 0.05 cm long; stigma crescent or semicircular shaped, 0.08 cm wide                                                                                                                                                                                                                                                   Column obconical. 0.12 cm long, 0.04 cm wide at base, 0.05 cm wide towards apex; foot 0.04 cm long; stigma semicircular in shape, 0.05 cm wide

  **Operculum attachment on column**   An inconspicuously separating arm on the top of column attached to the front broader part of operculum                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    An extension from the upper part of column protruding out and attached to the top of operculum                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      Broader front of operculum embedded in the column (no extension projecting from column on to operculum)                                                                                                                                                                                                                                                                                                        Almost half of the broader part of operculum embedded on to the top of the column (no extension projecting from column on to operculum)

  **Rostellum**                        Well developed with two semi-transparent, clavate, rostellar arms projecting in the front above stigma, 0.06 cm long.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     Well developed with two semi-transparent, clavate, rostellar arms projecting in the front above stigma, 0.05 cm long                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                Not visible or absent                                                                                                                                                                                                                                                                                                                                                                                          Not visible or absent

  **Pollination**                      Allogamous                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                Allogamous                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          Autogamous (due to lack of rostellum, pollinia falls on the stigma on its own)                                                                                                                                                                                                                                                                                                                                 Autogamous (due to lack of rostellum, pollinia falls on the stigma on its own)
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Based on preliminary chromosome counts, *Spiranthes himalayensis* and *S. nivea* both have a diploid chromosome number of about 30, similar to *S. sinensis.* It has been confirmed that *S. hongkongensis* is an allotetraploid (4× = 60), with *S. sinensis* as its maternal progenitor ([@B19], [@B2]) and most likely the new species *S. himalayensis* as its paternal progenitor (Surveswaran and Sun, unpublished). *S. hongkongensis* was not included in the phylogeny because it is a well-known allotetraploid ([@B19]) and sequencing of cloned ITS sequences of *S. hongkongensis* to identify the paternal and maternal progenitors of this species has been performed (Surveswaran and Sun, unpublished).

Supplementary Material
======================

###### XML Treatment for Spiranthes himalayensis

We thank, Joy Horam for field assistance, Professor Suhua Shi for help with Yunnan samples and Dr. K. Ravikumar (FRLHT, India) for providing some information on new occurrences. This work was supported by a HKRGC grant (GRF-17101616) and a CRCG grant (201511159168) to Mei Sun.

[^1]: Academic editor: V. Droissart
