ASCLEPIADE^E 223 



ASCLEPIADE.E. 



Benth. et Hook. Gen. PI. ii. 728. 



Fruit and Seed. The orary is superior and consists of two 

 distinct carpels, with their placentas on the ventral suture. 

 The stigmas are however confluent into one. The ovules 

 are numerous in each carpel, arranged in many series and 

 imbricated, the uppermost being outermost, pendulous, ana- 

 tropous, from a slightly prominent placenta. The fruit consists 

 of two erect or widely spreading follicles, or one of them may 

 be aborted, sessile, oblong, ovoid, or elongated, or fusiform, 

 smooth, nauricate, or many-winged, dehiscing by the ventral 

 suture, often breaking away from the placentas. The seed is 

 ovate, oval, oblong or elliptic, dorsally much compressed and 

 often surrounded with a thin margin. The testa is mem- 

 branous or coriaceous and often crowned with a long silky tuft 

 of hairs as occurs in Apocynaceae. Endosperm is present, 

 usually copious and cartilaginous. The embryo is straight 

 and axile, nearly equalling the endosperm in length with 

 broad flat cotyledons and a short superior radicle. An ex- 

 ception to the above characters occurs in Atherandra where 

 the ovary is half inferior. The terminal pencil of hairs is 

 absent from the seeds of Finlaysonia and Sarcolobus (tropical 

 Asia) and of Gonolobus stenopetalus (Mexico). 1 



The embryo of Periploca laevigata nearly equals the endo- 

 sperm in length and has foliaceous, broadly oblong cotyledons. 

 Several seeds examined contained two embryos. The seeds 

 are surmounted by a coma which falls early. The same may 

 be said of Stephanotis floribunda, the comose tuft of hairs of 

 which is long, white and silky. The object of the coma is 

 evidently for the distribution of the seed, but the thin and 

 almost winged character of the latter renders the coma of 

 less importance than it otherwise would be. The fruit 

 consists of two very large fleshy follicles with exceedingly 

 numerous seeds. The cotyledons are suborbicular. 



1 A. Gray, Proc. Amcr. Acad. xxi. 398. 



