CRUDE DRUGS. 



431 



Inner Structure. See Figs. 186; 284, A; 306. 



Constituents. Strophanthin, a crystalline principle occur- 

 ring chiefly in the endosperm and varying from 0.95 to 3 per cent. ; 

 strophanthin is colored greenish with sulphuric acid, and yields on 

 decomposition a crystalline body called strophanthidin ; the other 

 constituents are kombic acid and about 30 per cent, of a fixed oil. 



Allied Plants. The seeds of a number of other species and 

 varieties of Strophanthus find their way into the market, but 



Fig. 185. A dehiscent follicle of strophanthus showing plumose seeds. 



these are usually more or less deficient in strophanthin and hence 

 do not give a greenish color v.ith sulphuric acid. The most 

 important of these are the seeds of Strophanthus hispidiis, a plant 

 growing in Upper Guinea and other parts of Western Africa. 

 These are smaller, thicker and less hairy than those of S. Komhe 

 and yield less than i per cent, of strophanthin. The commercial 

 drug may contain other Strophanthus seeds, some of which con- 

 tain calcium oxalate prisms. 



