These nematodes, sold under the names of Scanmask and Nemasys, are microscopic, wormlike creatures that will destroy the fungus gnats but are not harmful to people, pets, plants, or earthworms. These products can be used whenever the soil is not frozen and will keep working for many months.
Vegetative structures. There are three levels of integrated organization in the vegetative plant body: organ, tissue system, and tissue. The organs of the plantâthe roots, stems, and leavesâare composed of tissue systems (dermal tissue, ground tissue, and vascular tissue; see below Tissue systems).
Large tracts of cells with a similar structure that form a collective function are referred to as tissues. Complex organs such as flowers, leaves, stems, roots and fruits are all made up of various types of tissues. There are two basic types of tissues: 1  Meristematic tissue is found in the roots and shoots of plants.esson Structure. There are 10 lessons in this course: 1  Taxonomic Classification of Plants. 2  Plant Taxonomy-Botanical/Horticultural Nomenclature, The Binomial System, Botanical Classification, Plant Families and Species, Hybrids, Varieties and Cultivars.