Page:First course in biology (IA firstcourseinbio00bailrich).pdf/83

 climbing when they cling to other objects for support (Figs. 36, 56).

(a twiner).

Trees in which the main trunk or the "leader" continues to grow from its tip are said to be excurrent in growth. The branches are borne along the sides of the trunk, as in common pines (Fig. 57) and spruces. Excurrent means running out or running up.

A pine.

Trees in which the main trunk does not continue are said to be deliquescent. The branches arise from one common point or from each other. The stem is lost in the branches. The apple tree, plum (Fig. 58), maple, elm, oak, China tree, are familiar examples. Deliquescent means dissolving or melting away.

Each kind of plant has its own peculiar habit or direction of growth; spruces always grow to a single stem or trunk, pear