GLOSSARY. 317 



various kinds: one style cuts on both sides of the row at 

 one time. 



Tri. Prefix, meaning three. 



Triangulation. The method of survey by dividing into triangles. 



Tripod. A three-legged support for an instrument. 



Turgid. Distended; applied to leaves and other parts when 

 filled with water. 



Umbel. An umbrella-like form of inflorescence (e.g. flower clus- 

 ters of Caraway, Parsnip). 



Unisexual. Bearing either male or female organs, not both (e.g. 

 flowers of Willows). 



Variety. A distinct and valuable variation from the original. 



Valve. One of the parts of a dehiscent pod. 



Valvate. Opening by valves. 



Volume. Amount or mass of a tree or log. 



Water capital. The entire water of the earth. 



Weed. A plant out of place, a generally troublesome plant, not 

 of any appreciable economic value. 



Whorl. Applied to leaves when arranged in a circle around the 

 stem. 



Wings of a leaf. The expanded portion; the blade. (Fig. 15.) 



Windbreak. A single row or belt of trees, which serves as a pro- 

 tection from wind. 



Wood. The hardened tissue of a stem; a forest. 



Working-plan. A prearrangement of the method of growing and 

 harvesting a forest crop of a particular tract. 



