DIADELPHIA— DECANDRIA. 259 



Keel of 1 petal, or more frequently of 2 combined, with 

 a double claw, boat-shaped, compressed, with a tooth or 

 prominence, on each side, at the base ; either rounded or 

 rectangular in front. 



All the petals expand in bright warm weather, and close 

 in darkness, cold, or damp. 

 Stamens diadelphous. Filaments 2, lodged in the keel, both 

 membranous and flattened, but usually differing in width, 

 rarely equal ; 1 embracing the pistil beneath ; the other 

 lying upon its upper edge; the former keeled, divided at 

 the summit into 9 slender awl-shaped parts ; the latter 

 awl-shaped, simple, slendei'. Anthers small, equal, ob- 

 long or roundish ; 9 on the broader filament ; 1 on the 

 narrower. In some instances there is but a single com- 

 pressed folded Jllament, terminating in 10 equally-divided 

 anther-bearing segments, various in length ; in others the 

 2 unequal Jilaments are either united or distinct at the 

 base. The latter only are strictly diadelphous ; but the 

 difference is of little moment, and not easily discernible. 

 Pistil solitary, superior. Germen sessile or stalked, oblong 

 or roundish, compressed, the length of the undivided part 

 of the \o\s ox filament^ by which it is embraced. Style ter- 

 minal, awl-shaped, ascending, the length of the separate 

 part of the filaments, or longer. Stigma downy, termi- 

 nal or longitudinal, capitate, or linear, or dilated. 

 Legume oblong or roundish, compressed or inflated ; either 

 of 2 continued valves, and 1, rarely imperfectly divided, 

 cell^ with a longitudinal suture above and below, the 

 former bearing a linear double receptacle ; or consisting 

 of 1 or more closed, single-seeded joints. 

 Seeds several, rarely solitary, roundish, tumid, pendulous, 

 on slender alternate stalks, from the upper suture of the 

 legume only, where it splits asunder, having one receptacle 

 to each valve. Separate albumen none. Cotyledons either 

 raised above ground in germination, becoming leafy, or 

 subterraneous and decaying. 

 The habit is either herbaceous or shrubby, annual or per- 

 ennial. Wood hard. Leaves pinnate ; either abruptly, 

 with more or less of a tendril; or with an odd leaflet; or 

 ternate ; or binate ; rarely simple. Stipidas in pairs, va- 

 rious and remarkable. Injlorescence various. FL hand- 

 some, often fragrant. Herbage wholesome for cattle ; 

 seeds, when dressed, for mankind. There is no noxious 

 British plant, nor scarcely an exotic one in the whole 

 order. 



s2 



