72 
PHARMACEUTICAL BOTANY 
piration stomata in that they always remain open, are circular in out- 
line, give off water in droplets directly, and lie over a quantity of 
small-celled glandular material which is in connection with one or 
more fibro-vascular bundles. Examples: Leaves of Crassula, Saxi- 
fraga and Ficus. 
The epidermis of leaves, stems, fruits, and seeds of many plants 
frequently give rise to outgrowths in the form of papillae, hairs 
and scales. Epidermal papilla are short protuberances of epidermal 
Fig. 22. — Upper epidermis of Comptonia aspleni folialeat (surface view) show- 
ing epidermal cells and two non-glandular trichomes. 
cells. They may be seen to advantage on the upper epidermis of the 
ligulate corolla of various species of Chrysanthemum, on the lower 
epidermis of the foliage leaves of species of Erythroxylon and upon the 
upper epidermis of the petals of the Pansy ( Viola tricolor). Epi- 
dermal hairs or trichomes are more elongated outgrowths of one 
or more epidermal cells. They may be unicellular (Cotton) or 
multicellular, non-glandular (simple) or glandular. The non- 
glandular hairs may be of various shapes, viz.: clavate (club-shaped) 
as on Rhus glabra fruits; stellate (or star-shaped) as on Deutzia 
leaves; candelabra-shaped, as on Mullein leaves; filiform as on 
