SUTURE, the part where separate organs unite, or where the edges of a folded organ adhere; the ventral suture of the ovary is that next the centre of the flower; the dorsal suture corresponds with the midrib. SYMMETRY, applied to the flower, has reference to the parts being of the same number, or multiples of each other. SYNANTHEROUS, anthers united together. SYNCARPOUS, carpels united so as to form one ovary or pistil. SYNGENESIOUS, same as Synantherous. T TAP-ROOT, root descending deeply in a tapering, undivided manner. TEGMEN, the second covering of the seed; called also Endopleura. TEGMENTA, scales protecting buds. TENDRILS, curling, twining organs, with which plants grasp supports. TERATOLOGY, study of monstrosities and morphological changes. TERCINE, the third coat of the ovule, forming the covering of the central nucleus. TERETE, nearly cylindrical. TERMINAL, at the top or end. TERNARY, parts arranged in threes. TERNATE, compound leaves composed of three leaflets. TESTA, the outer covering of the seed; some apply it to the coverings taken collectively. TETRADYNAMOUS, four long stamens and two short, as in _Cruciferæ_. TETRAGONOUS, having four angles. TETRAMEROUS; a flower is tetramerous when its envelopes are in fours. TETRASPORE, a germinating body in Algæ, composed of spore-like cells, but also applied to those of three cells. THALAMIFLORAL, parts of the floral envelope inserted separately into the receptacle of the thalamus. THALAMUS, the receptacle of the flower, or the part of the peduncle into which the floral organs are inserted. THALLOGENS, or THALLOPHYTES, plants producing a thallus. THALLUS, cellular expansion in lichens and other cryptogams, bearing the fructification. THECA, sporangium or spore-case, containing spores. THROAT, the orifice of a gamopetalous corolla. THYRSUS, a sort of panicle, in form like a bunch of grapes, the inflorescence being mixed. TIGELLUS, the young embryonic axis. TOMENTOSE, covered with cottony, entangled pubescence, called tomentum. TOMENTUM, dense, close hair. TOOTHED, dentated. TORUS, another name for Thalamus; sometimes applied to a much-developed thalamus, as in _Nelumbium_. TRANSPIRATION, the exhalation of fluids by leaves, etc. TRIADELPHOUS, stamens united in three bundles by their filaments. TRIANGULAR, having three angles, the faces being flat. TRICHOTOMOUS, divided successively into three branches. TRIFOLIATE, or TRIFOLIOLATE, same as Ternate. When the three leaves come off at one point the leaf is _ternately trifoliate_; when there are a terminal stalked leaflet and two lateral ones, it is _pinnately trifoliate_. TRIGONOUS, having three angles, the faces being convex. TRIMEROUS; a trimerous flower has its envelopes in three or multiples of three. TRIPARTITE, deeply divided into three.