226 ON THE ASCLEPIADEiE. 



Obs. Asclepias cordata, Forsk. Arab. p. 49, and Cy- 

 nanchum extensum, Jacq. ic. 1, t. 54, are the only certain 

 species of the genus : from the latter, Asclepias scandens, 

 Palis. Flor. D'Oware, I, p. 92, t. 56, is probably not dis- 

 tinct, and Cynanchum bicolor, And. Hepos. 562, is very 

 nearly related to it. 



SARCOSTEMMA. 



Char. Corolla rotata. 



Corona staminea duplex ; exterior cyathiformis v. annu- 

 laris, crenata ; interior 5phylla, exteriorem superans, foliolis 

 carnosis. 



Anther a membrana terminate. 

 si] Masses pollinis apice affixse, pendulse. 



Stigma subrauticum. 



Folliculi graciles, lseves. Setnina comosa. 



Habitus. Caulis volubilis v. decumbens, aphyllus, arti- 

 culatus, v. foliis oppositis distantibus. Flores umbellati, 

 laterales v. terminales. 



Patria. India Orientalis, Nova Hollandia, et Africa. 



Obs. To this genus belong Cynanchum viminale, Linn. ; 

 a species nearly allied to it from New Holland and New- 

 Caledonia ; and Asclepias viminalis, Linn., all of which I 

 have examined. The probable species are, Asclepias 

 aphylla, Thunb. prod. ; Asclepias stipitacea, Forsk. Arab. 

 50 ; Cynanchum pyrotechnicum, and perhaps also Ascle- 

 pias aphylla, of the same author. 



EUSTEGIA. 



Char. Corolla rotata. 



Corona triplex ; singula 5phylla ; extima fauce inserta 

 laciniis limbi opposita ; reliqua extima alternantia, antheris 

 opposita, foliolis medics tripartitis, intimes indivisis. 



Anther <b membrana terminate. 



Masses pollinis apice attenuato aflixae, pendulse. 



