Tankage An organic fertilizer that leaves an alkaline reaction.
Tannin A complex, aromatic compound occurring in the bark of many shrubs and trees.
Taproot The main, descending root of a Plant with a single dominant root axis.
Tautonym An inadmissable name where the genus name is the same as the species name.
Taxon A group of plants of the same type, e.g., species, genus, family, order etc.
Tegmen The inner layer of the testa (seed coat). It develops from the inner integument of the ovule.
Temperate Pertaining to the cooler areas of the world with moderate climates.
Tendril A slender twining appendage or extension by which a climbing plant may attach itself.
Tenuiexinous of a pollen grain, with a thin exine.
Tepal Perianth segment, either sepal or petal; usually used when all perianth segments are similar in appearance.
Terete Circular in cross-section; more or less cylindrical.
Terminal Situated at the tip or apex.
Ternate In threes, as a leaf which is divided into three leaflets.
Ternatifid of leaves, deeply cut into three lobes.
Ternatisect Cut into three lobes or partial divisions.
Terracotta A brownish-orange eearthenwar used to make pots.
Terrarium An enclosed environment for plants or animals where they are kept alive for study and observation.
Terrestrial Growing on the ground.
Testa Seed coat.
Tetrad A group of four, usually means four pollen grains remaining fused together a maturity.
Tetradynamous Having six stamens, four of which are long, as in the Cruciferae.
Tetragonous having four angles.
Tetragynous Having four pistils or carpels.
Tetrahedral of a solid with four sides.
Thalamus A receptacle; the end of the Flower stalk where the flowers are carrif, which is often slightly enlarged.
Thalliform Having the form of a thallus.
Thalloid Plants which have no roots, stem, or leaves. Such as, liverworts and hornworts.
Thallour Flat, ribbon-shaped.
Thallus Plant body not differentiated into leaves and stem.
Theca A case or sac, generally the same as a capsule.
Thorn A woody, sharp-pointed, modified stem.
Throat The opening of a corolla or perianth.
Thyrse A branched inflorescence in which the main axis is indeterminate and the lateral branches determinate in their growth.
Thyrsoid Resembling a thyrse.
Tigella A short stem.
Tigellate Having a short stalk, such as that of a bean.
Tilth The condition of a soil in respect to its ability to support the growth of a specific type of plant.
Tomentellous Minutely tomentose.
Tomentose Covered with not very long cottony hairs, more or less felted together, shorter and less dense than lanate.
Toothed With a more or less regularly incised margin.
Torose Knobbed.
Trabecula A tranverse partition dividing or partly dividing a cavity.
Tracheophyte Any member of the clade of plants possessing vascular tissue; a vascular plant.
Trachycarpous Having rough fruit.
Trachyspermous Rough-seeded.
Translucent letting light through, almost transparent.
Transpiration The loss of watery vapor from the surface of foliage.
Trapeziform A plane, asymmetric shape with four straight sides of unequal length.
Tree A woody plant, usuallx with a single distinct trunk and generally more than 5m tall.
Triad A group of three.
Triandrous having 3 stamens.
Tribe A taxonomic grouping, in rank between genus and species.
Trichome Any type of plant hair.
Trichotomous three-forked.
Tricostate three-ribbed.
Tridactylate Three-fingered, with three narrow lobes.
Trifid divided into three equal parts, usually to about half-way.
Trifoliate having three leaves.
Trifurcate Split into three forks or branches.
Trigonous Triangular in cross-section and obtusely angled.
Trijugate Having three pairs of leaflets.
Trilete of a spore with a radial, three-armed scar.
Trilobate Three-lobed, such as a leaf.
Trimorphism The development of three distinct forms of flowers, leaves, or other parts upon the same plant, or upon plants of the same species.
Trinerved having three nerves or veins.
Tripartite divided into three parts.
Tripinnate of leaves, thrice pinnately divided.
Triplicate folded 3 times.
Triplinerved having three main nerves with the lateral nerves arising from the midnerve above the base of the leaf.
Triquetrous triangular in cross-section and acutely-angled; with 3 distinct longitudinal ridges.
Tristachyous Three-spiked.
Tropic Pertaining to the warmer or equatorial regions of the world.
Trullate Shaped like a brick-layer's trowel.
Truncate With the base or apex flattened abruptly as though cut off.
Trunk the erect, unbranched portion of a tree-like plant.
Tuber a storage Organ Formed by swelling of an underground stem or the distal end of a root.
Tubercle A small wart-like outgrowth.
Tuberculate bearing knobby projections.
Tuberoid An underground storage organ formed by the swelling of a root; occurs in many orchids.
Tuberous Swollen; of roots, tuber-like.
Tubuliflorous When all the flowers of a head have tubular corollas, such as in the Campanulaceae and the Compositae.
Tuft A densely packed cluster arising from an axis.
Tumid Swollen; inflated.
Tump To form a mass of earth or a round embankment.
Tunic Outer covering of some bulbs and corms.
Turbinate top-shaped.
Turgid Swollen, rigid and stiff by means of internal pressure.
Turgor pressure Force exerted outward on a cell wall by the water contained in the cell. This force gives the plant rigidity, and may help to keep it erect.
Turion An over-wintering vegetative bud or specialised short shoot with modified leaves, arising from the stem, often near ground level.
Tussock A dense tuft of vegetation, usually well separated from neighbouring tussocks, for example some grasses.
Twig The relatively small end portion of a woody branchlet; a small branchlet.
Twiner A climbing plant supporting itself by winding spirally around an object.
Typical variant The variant of a species to which belongs the type specimen of that species.
