CLXVIIT. ACANTHACE^E. 



C05 



or contracted into a pedicel, 

 obtuse 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, which 

 is sometimes reduced to a mere 

 cupule; testa soft, or covered 

 with mucilaginous hairs. EM- 

 BRYO 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-ORDER I. THUNBERGIDE^E. 



Calyx reduced to a ring. 

 Corolla-lobes contorted. Seeds 

 with a cupuliform funicle. Stem 

 usually twining. Thunbergia (Hex- 

 acentris). 



SUB-ORDER II. RUELLID^E. 



Calyx herbaceous, 5- (rarely 

 4-) partite. Corolla-lobes contorted. 

 Seeds inserted on a hooked reti- 

 naculum or on a papilla. Stem 

 not twining. 



TRIBE I. NELSONIE.E. Calyx 

 small, herbaceous. Seeds minute, 

 globose, inserted on a small papilla. 

 Elytraria, Ebermayera, Nelsonia, 

 Adenosma. 



Acanthus 



