LEAVES. 



79 



PLATE XXXIII. 



FIG. 43. Powdered Rue Leaves (x 240). 



en, Large cluster crystals. 



ei, Lower epidermis. 



en, Neural epidermis. 



es, Upper epidermis with pitted cell-walls. 



I, Bast. 



m, Spongy parenchyma. 



pa, p'a', Palisade cells. 



st, Stomata surrounded and partially overhung by four or five cells. 



tf, Cortical tissue of tne midrib. 



tp, v, Tracheids and vessels. 



No hairs, either simple or glandular. 



