STROPHANTHUS 



543 



flowers and follicles (Fig. 231). The root resembles that of A. canna- 

 binum, but is easily distinguished by the presence of small groups of 

 stone cells in the outer cortex (Fig. 232). 



A i <"'. .<i i B 



K 



K_ 



FIG. 232. A, transverse section of the root of Apocynum cannabinum showing 

 cork (K); laticiferous tubes (L) in the cortex; sieve (S), beneath which is 

 the cambium zone; wood fibers (SF), tracheae (T), and medullary rays 

 (MR). B, transverse section of the root of Apocynum androsaemifolium 

 showing in addition groups of stone cells (Si) in the cortex. 



Literature. Holm, Merck's Report, 1910, p. 277; Power, Jour. 

 Chem. Soc., 1909, p. 734. 



I Strophanthus. The ripe seeds of Strophanthus Kombe (Fam. 

 Apocynacese), a twining shrub found in Zambesi and other parts of 



