544 BOTANY AND PHARMACOGNOSY. 



but is reddish-brown, and tinges the saliva yellowish ; it contains 

 besides tannin a yellow glucosidal principle quercitrin, which 

 yields quercetin, a yellow coloring principle. 



ULMUS.— SLIPPERYrELM BARK.— The bark of Ulmiis 

 fiilva (Earn. Ulmacese), a tree indigenous to the Eastern and 

 Central United States and Canada (p. 254). The bark is col- 

 lected in spring (Fig. 238), deprived of the periderm and dried, 

 the commercial article coming chiefly from Michigan. 



Description. — In flat oblong pieces about 30 cm. long, 10 to 

 15 cm. in diameter, 3 to 4 mm. thick; outer surface light brown, 

 longitudinally wrinkled and furrowed and with occasional dark- 

 brown patches of periderm; inner surface yellowish or light 

 brown, more or less uniformly wrinkled longitudinally; fracture 

 fibrous, surface light brown, porous from large mucilage cells; 

 odor slight, distinct ; taste mucilaginous. 



Inner Structure. — See Fig. 99, C: 



Constituents. — The principal constituent is mucilage ; it also 

 contains starch and calcium oxalate. 



Allied Plants. — Ulmus campestris, or European elm, yields 

 a bark which is dark brown, and contains, besides mucilage, a 

 bitter principle and tannin. 



QUASSIA.— QUASSIA WOOD.— The wood of Picrasma 

 excelsa (Fam. Simarubacese), a tree indigenous to Jamaica and 

 other islands of the West Indies (p. 309). The trees are felled 

 and cut into billets. The latter are exported and afterward man- 

 ufactured into " quassia cups," the shavings constituting the drug 

 known as Jamaica Quassia. The market supply of this drug was 

 at one time almost exclusively obtained from Quassia amara 

 (Fam. Simarubacese) , a small tree (Fig. 159) indigenous to 

 Brazil and cultivated in Columbia, Panama, West Indies and 

 other tropical countries (p. 309). The wood exported from 

 Surinam is known as Surinam Quassia ; this is the variety used 

 in continental Europe and is now also official. 



Jamaica Quassia. — Usually in raspings, light or bright yel- 

 low, medullary rays two to five cells wide in transverse section 

 (Fig. 239, A), the cells containing tetragonal prisms or crypto- 

 crystalline crystals of calcium oxalate; fracture fibrous; odor 

 slight; taste bitter. 



