192 PLANT ORGANS OR PARTS OF PLANTS. 



Chemistry. — The main ingredients are hyoscyamine, 

 an alkaloid, and hyoscine, also an alkaloid, and some 

 potassium nitrate. The exact composition of hyoscya- 

 mine is not yet determined. 



PILOCARPUS. 



Pilocarpus is the leaflets of Pilocarpus selloanus and 

 Pilocarpus jahorandi, respectively termed Rio and Per- 

 nambuco jaborandis. These plants are low shrubs, 

 usually from four to six feet high, and inhabit the forests 

 and cleared hillsides of Brazil. A large number of species 

 are known, some eight to ten of which have been described 

 as occurring in the markets.* These species are some- 

 times used as adulterants, and in addition some ten to 

 twelve allied plants have been figured, all of which have 

 at various times been used for sophistication. The 

 plants of the pharmacopoeial species are now under culti- 

 vation. 



Description. — Dried jaborandi leaves are usually green- 

 ish-brown in color and oblong-lanceolate in shape, vary- 

 ing from t.wo and a half to four inches. The apex is 

 blunt and emarginatc, the margin entire and re volute. 

 The base is usually rounded and unequal and attached to 

 a short stalk. Upon the upper surface the lateral vessels 

 are distinct; the lower surface is glabrous, but sometimes 

 bears a few scattered hairs. 



Histology.- The following elements may be identi- 

 fied: Leaf epidermis with stomata, leaf mesophyll, 

 fibrous tissues from the midribs and petioles, oil glands, 

 crystals, starch, hairs, and sometimes stone cells. 



The leaves of pilocarpus are dorsiventral ; the stomata 

 are confined to the lower surface, hence in the powder 

 upper and lower leaf surfaces are to be differentiated.* 



The upper epidermal cells are usually regularly poly- 

 gonal, they vary greatly in average diameter in the 



*H. H. Rusby, Druggists' Circular, 1902. 



