TENDRIL: A spirally, coiling, thread-like organ that attaches itself to another body for support, as in the Grapevine or Virginia Creeper. A tendril may be a modified stem, branch, leaf, or stipule.
TENSION: A term related to soil moisture and the equivalent negative pressure of suction of water in the soil.
TEPAL: In some flowers, such as the Tulip and Begonia, the calyx and corolla aren't clearly differentiated; the proper name for one of these petal-like parts is tepal.
TEPEE: This is a cone-shaped structure consisting of three or more stakes bound together near the peak used to grow vine crops such as peas, beans, and cucumbers.
TERETE: Pencil-like; round in cross-section; cylindrical, but usually tapering at both ends, such as a terete seedpod.
TERMINAL: Growing at the tip of a branch or stem, often applied to a bud, rosette, or flower.
TERNATE: Arranged in three's; especially said of a leaf with three leaflets, or of leaves whorled in three's. If the three divisions of a ternate leaf are subdivided into three leaflets each, the leaf is biternate, and yet another subdivision is called a triternate leaf.
TERNATISECT: Cut into three lobes or partial divisions.
TERRACE: 1. A ridge made across sloping soil on the contour or at a slight angle to the contour that intercepts and delays surplus water for absorption into the soil. All excess water may be forced to flow slowly into prepared outlets. 2. A raised level faced with masonry or turf; an elevated flat space, such as a garden terrace; also, a natural formation of the ground resembling such a terrace.
TERRACOTTA: A brownish-orange earthenware used to make pots.
TERRARIUM: An enclosed environment for plants or land animals; a place where such plants or animals are kept alive for study or observation.
TERRESTRIAL: Means a plant which derives its nutrients from the soil rather than atmospheric moisture as do ephiphytic plants or the water as do aquatic plants. Some Orchids are epiphytes and some are terrestrial. Water Lilies are an aquatic plant.
TESSELLATION: A checkered pattern.
TESTA: The hard outer coating of a seed; episperm.
TETRA-: Having four, as in tetrachord, tetragon, tetramerous, tetrapetalous, tetraspermous.
TETRADYNAMOUS: Having six stamens, four of which are long, as in the Cruciferae.
TETRAGYNOUS: Having four pistils or carpels.
TETRAMEROUS: Having the parts in sets or multiples of fours; often written 4-merous.
TETRANDROUS: Having four stamens.
TEXTURAL CLASS: The type or classification of soil material determined by the proportion of sand, silt, and clay in its makeup.