Page 71 – Marginal spines on leaves
Fig. . Marginal spines on leaves. Longitudinal sections of a young (i.e., seedling) leaf, A, and of a fully differentiated leaf, B, to show an early stage in the development of and a mature spine, respectively. ep, epidermal cells (in surface view) on another leaf showing an early stage of stoma formation (gc) and of trichomee (th); hp, hypodermal layers of spine; lm. leaf margin; mes, mesophyll; ra, raphides; spa, apical growing region of spine. A, X200; B, X800.