Thyrse. A compact, compound panicle with an indeterminate axis (fig. 788). 



Tomentose. Densely covered with short, matted hairs (fig. 785). 



Tomentum. Pubescence of densely matted short hairs. 



Toothed. Bearing teeth. 



Torus. Specifically, the structure of a flower surrounding the gynoecium and bear- 

 ing the other flower parts on its margin; may be used for any tubular out- 

 growth that originates as a ring of growth from the meristem. 



Tri-. A Latin prefix signifying three, thrice, or triply. 



Trichome. A hair or hairlike structure. 



Trico.state. Having three ribs. 



Trifid. Cleft into three parts. 



Trifoliate. Bearing three leaves, as does Trillium. 



Trifoliolate. Having a leaf comprised of three leaflets, as does clover. 



Trigonous. Said of an achene or other structure which is three-sided or triangu- 

 lar in cross section (fig. 222). 



Triquetrous. Having three projecting angles. 



Truncate. Cut squarely across, either at the base or at the apex (fig. 787). 



Tube. The narrow basal portion of a gamopetalous corolla or a gamosepalous 

 calyx. Tubiform: tubular or trumpet-shaped. 



Tuber. An enlarged, fleshy, underground stem, such as the potato (fig. 234). 



Tubercle. A nodule on the surface, or a thickened, solid or spongy crown or cap, 

 as on an achene. 



Tuberculate. Bearing tubercles on the surface. 



Tubular. Cylindrical and hollow. 



Tufted. With a dense cluster of elongate structures spreading from what appears 

 as a common point of attachment. 



Tumid. Swollen. 



Tunicated. Said of a bulb having its scales arranged in concentric layers as in the 

 bulb of an onion (fig. 789). 



Turbinate. Inversely conical, or top-shaped. 



Turion. A scaly, often thick and fleshy, shoot produced from a bud on an under- 

 ground rootstock, as in some species of Potamogeton. 



Umbel. An inflorescence of few to many flowers on stalks of approximately equal 

 length arising from the top of a scape or peduncle (fig. 788). 



Umbellate. Arranged like an umbel (fig. 223). 



Umbellet. The umbel-like segment of a compound umbel (fig. 788). 



Uncinate. Hooked at the tip. Uncinulate: the diminutive. 



Undulate. Having a wavy margin; said of leaves, petals, or sepals (fig. 787). 



Uni-. A prefix, meaning one. 



Unisexual. In flowering plants, said of a plant or flower that either bears only sta- 

 mens or only pistils, but not both. 



Urceolate. Said of a corolla with united petals and a tube that is expanded below 

 the middle and narrowed at the top. 



Utricle. A usually one-seeded, indehiscent fruit with a thin, bladdery, persistent 

 ovary wall (fig. 789). 



Vaginate. Loosely surrounded by a sheath. Vaginiform: sheath-shaped. 

 Valvate. Said of appendages (leaves, sepals, petals, or carpels) when arranged 



margin to margin with adjacent structures in the bud, or in the fruit. 

 Valve. A rigid or semirigid segment joined to adjacent structures by its margin. 

 Vascular bundles. The elements of the conducting or vascular system of a plant. 



1731 



