CLXVIIT. ACANTHACEiE. 



605 



or contracted into a pedicel, 

 obtiise or acute, 2-celled, some- 

 times opening elastically into 2 

 boat-shaped semi - septiferous 

 entire or 2 -partite valves, 

 sometimes indehiscent by ar- 

 rest of one of the cells. Seeds 

 rounded or compressed, gene- 

 rally supported by subulate or 

 hooked processes (retinacula) 

 arising from the septum, vphich 

 is sometimes reduced to a mere 

 cupule; testa soft, or covered 

 with mucilaginous hairs. Em- 

 BKYO exalbuminous, usually 

 curved ; cotyledons large, orbi- 

 cular, plano-convex, sometimes 

 crumpled ; radicle cylindric, 

 descending and centripetal. 



[The Asiatic and African 

 genera of Acanthacece have been 

 grouped as follows by Dr. 

 Thomas Anderson, who con- 

 siders that the American and 

 other genera will fall under the 

 same tribes : — 



SuB-OEDEE I. THUNBERGIDE^. 



Calyx reduced to a ring. 

 CoroUa-lolies contorted. Seeds 

 with a cTipuliforni fnnicle. Stem 

 usually twining. Thimbergia (JEex- 

 aceniris). 



SuB-OEDEE II. RUELLIDJi!. 



Calyx herbaceous, 5- (rarely 

 4-) partite. Corolla-lobes contorted. 

 Seeds inserted on a hooked reti- 

 naculum or on a papilla. Stem 

 not twining. 



Teibe I. Nelsonib^. — Calyx 

 small, herbaceous. Seeds minute, 

 globose, inserted on a small papilla. 

 Elytraria, JEhermayera, Nelsonia, 

 Adenosma. 



Acanthus moUU. 



