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taenia - n. (Gr. tainia, a ribbon or tape)
formation of ribbon-like structure with little
or no differentiation between the leaf blade
and stem.
tannins - n. (L. tannum, oak bark) complex aromatic compounds some of which are glucosides, possibly giving protection or concerned with pigment formation. taxon - n. (Gr. taxis, arrangement) a taxonomic category or unit, as a species or genus. taxonomy - n. (Gr. taxis, arrangement; nomos, law) a science that includes identification, nomenclature, and classification of objects, and is usually restricted to objects of biological origin; orderly classification of plants according to their presumed natural relationships forming a basic biological discipline involving during its Linnean period the firm establishment of binomial nomenclature and acceptance of the static concept of fixity of the species, during its Darwinion period the dynamic concept of speciation by natural selection, and during its modern Mendelian epoch an expansion to include study of the mechanisms underlying speciation and related processes. tendril - n. (O.Fr. tendrillon, tender sprig) a slender twining or clasping process, modified stem, leaf, or part of a leaf, by which some plants climb. tepal - n. (Fr. tepale, from petale) denoting a unit of the perianth when the sepals and petals are essentially alike and not readily differentiated. terete - a. (L. teres, round, smooth) nearly cylindrical in cross-section, as stems. ternate - a. (L. terni, three each) growing in groups of threes, as some leaves. testa - n. (L. testa, shell) the hard outer covering or integument of seed. Thallophyta - n. pl. (Gr. thallos, a young shoot; phyton, a plant) a primary division of plants including all forms consisting of one cell and cell aggregates not clearly differentiated into root, stem, and leaf, including bacteria, algae, fungi, and lichens. thalloid - a., of or resembling a thallus. thallus - n. (Gr. thallos, a young shoot) a plant body that lacks differentiation into distinct forms of stems, leaves, roots, and does not grow from an apical point. therophytes - n. (Gr. theros, summer; phyton, a plant) an annual plant that overwinters as a seed. thorn - n. (ME., fr. OE.; akin to OHG. dorn, thorn, ON. thorn, Goth. thaurnus, thorn, Skt. trna, grass, blade of grass) a sharp rigid process on a plant; specif., a short, indurated, sharp-pointed, and leafless branch developed from a bud in a manner typical to a leafy branch. throat - n. (Gr. drossel, the gullet) term applied to an expanded part of a corolla tube just below the lobes. thyrseus - n. (Gr. thyrsos, wand) a panicle-like inflorescence consisting of a slender indeterminate main axis with lateral axes determinate, i.e., cymose. tiller - n. (OE. telgor, telgra, branch, twig, shoot) sprout, stalk, especially one from the base of a plant or from the axils of its lower leaves. tissue culture - the use of specialized methods to mass produce plants starting with small amounts of plant tissue. tomentose - a. (L. tomentum, down) densely covered with short, matted hair. Tracheophyta - n. (LL. trachia, windpipe; and Gr. phyton, plant) a division of plants comprising green plants with a vascular system that contains tracheids or tracheary elements, being the Pteridophyta and Spermatophyta, commonly called vascular plants. trichome - n. (Gr. trichoma, a growth of hair) an outgrowth of the plant epidermis, either hairs or scales; a hair tuft; any hairlike outgrowth of the epidermis. trigonal - a. (Gr. trigonos, triangular) triangular in cross-section as applied to stems. trigonous - a., trigonal; having three prominent longitudinal angles, as a style or ovary. triploid - n. (Gr. triplus, triple) having or being a chromosome number three times the monoploid number. trimerous - a. (Gr. tria, three; meros, part) composed of three or multiples of three. triquetrous - a. (L. triquetrus, three-cornered) triangular; having a triangular cross section. tristichous - a. (Gr. tria, three; stichos, row) arranged in three vertical rows. truncate - a. (L. truncatus, cut off) terminating abruptly, as if tapering end were cut off; cut squarely across, either at the base or apex of an organ. trunk - n. (OFr. trone; fr. L. truncus, a trunk, stock, stem) the main stem or body of a tree, considered apart from its roots and branches. tuber - n. (L. tuber, a swelling or knob on plants) the short, thickened fleshy food-storing portion of an underground stem with many surface buds, generally shaped like a rounded protuberance. tubercle - n. (L. tuberculum, a swelling) a small rounded protuberance; root swelling or nodule; bubil; a surficial nodule; a thickened, solid, spongy crown or cap, as on an achene; a small tuber or tuberlike growth. turbinate - a. (L. turbinatus, whirl, rotation) inversely conical; shaped like a cone resting on its apex. turion - n. (L. turio, shoot) young scaly shoot budded off from underground stems, detachable winter bud used for perennation in many aquatic plants. twig - n. (AS. twigge, twig) a small shoot or branch of a tree or other plant.
umbel - n. (L. umbella, dim. of umbra shadel) an arrangement of flowers springing from a common center and forming a flat or rounded cluster. umbellate - a., bearing umbels; consisting of umbels; forming an umbel or umbels. unisexual - a. (L. unus, one; sexus, sex) of one or other sex, staminate or pistillate only, but not both. urceolate - a. (L. urceolus, a pitcher) shaped like a pitcher or urn. utricle - n. (L. utriculus, a little bag or bottle) an air bladder of aquatic plants; membranous indehiscent 1-celled fruit. |