Trees of the Northern United States 149 



Tetramerous. Four-parted. 



Thorn. A highly modified sharp-pointed l)ranch. 



Thorn-like spur. A short stunted branch ending in a sharp 



point or thorn. 

 Tomentose. Covered with dense wool-like hairs. 

 Triadelphous. Having stamens united by their filaments into 



three bundles. 

 Trilocular (3-locular). With three cavities. 

 Trimerous. Three-parted. 

 Truncate. Terminating abruptly by a nearly straight edge or 



surface. 

 Two-ranked. Disposed in two vertical rows along the twig ; 



with the third leaf in line with the first. 



Umbel. A determinate inflorescence with all the peduncles 



or pedicels arising from the same point. 

 Undulate. With wavy margins. 

 Unilocular (1-locular). With one cavity. 

 Utricle. A one-seeded fruit with a loose pericarp. 



Valvate. Meeting by the margins in the bud. not overlap- 

 ping ; dehiscent by valves. 



Vascular bundle. The conducting strands in the plant body 

 composed of wood and liast in which water and food 

 materials are conducted through the roots, stems and 

 leaves. 



Vein. One of the l)ranches of the vascular i)ortion of leaves 

 or other organs. 



Venation. The arrangement of the veins. 



Vernation. The arrangement of the leaves in the bud. 



Versatile. An anther attached at or near its middle to the 

 filament. 



Verticillate. Whorled. 



Villous. With long, soft hairs not 'matted together. 



Whorled. A group of three or more similar nrgans radiat- 

 ing from a node. 

 Winged. With a thin expansion. 



Xerophyte. A plant adapted to desert conditions. 



Zygomorphic. A flower or organ wliich can be cut into sim- 

 ilar halves bv onlv one plane. 



O. H, HIUL ummAWY 



North Carollmi State CotU 



