214 



DIOSCOKEACEJE. 



[DlCTYOGENS. 



The embryo of some geucra (Dioscorea, and Rajania) consists of a small oblong 

 plumule lying at the base of a thin veiny flattened cotyledon, and bears much resem- 

 blance to some Dicotyledonous einbryo with one cotyledon cut off. A similar con- 

 dition of the parts occurs in all except Tamus ; whence an additional argument may 

 be drawn for considering this order at least as being intermediate between Exogens 

 and Endogens. 



Tamils, L. 



Tanwvug, .hi>s. 

 Testudinaria, Oalisb. 

 Helmia, Kth. 

 Rajania, L. 



GENERA. 



Jan raja, Plurn. 

 Dioscorea, L. 



Ubioiii. Rumph. 

 § Centrostemon, Oris. 

 § Dematostemon, Grit. 



§ Aruphistemon, (iris. 

 § Epistemon, Gris. 

 § Lychnostemon, Oris. 

 § Allaotostemon, Gris. 

 Moment, Mart. 



§ Heniideniatostenion, 



Gris. 

 Oucus, I/)ur. 

 Podianthus, Scknitzl. 



Numbers. Gen. 7. Sp. 150. 



Position. Dioscoreace.e. — Smilaceaj. 



A rUtolochiacece. 



