10 FLORIDA VELVET BEAN AND RELATED PLANTS. 



native to the East Indies but which also occurs now in Jamaica and 

 other West Indian Islands, probably as an introduction; Stizolobium 

 pruritum (Mucuna prurita Hook, in Wight and Arnott, Prodromus 

 Florae Indise Peninsular Orientalis, 1834, vol. 1, p. 255); and Stizolo- 

 bium Mrsutum (W. and A.) Kuntze (Mucuna hirsuta Wight and 

 Arnott, op. cit., p. 254), both of the latter native to India. Only one 

 of these species with stinging hairs on the pods has matured in our 

 trials, namely, S. P. I. No. 25263, Stizolobium pruriens (?). None 

 of these species with stinging hairs can be utilized as forage crops, 

 but they have been grown with the idea of ascertaining their rela- 

 tionship to the more valuable forms. 



All of the stizolobiums possess something in the juice, especially 

 in the green pods, which rapidly turns black on exposure to air. This 

 substance blackens the hands and clothing of workmen cutting vel- 

 vet beans for hay, which is occasionally done. It also causes the 

 dried flowers and pods to become black, and does the same to the 

 seeds of white-seeded varieties, especially if gathered too green or 

 where they press upon each other. 



Botanical descriptions and economic notes concerning nine species 

 are presented in this publication. 



ANALYTICAL KEY TO THE SPECIES. 



Pods velvety with black pubescence. 



Seeds marbled, rarely white, thick, subglobose; pods 2.5 to 3 inches long, nearly 



as thick as broad deeringianum. 



Seeds black, oblong, somewhat flattened; pods flattened, 4 to \\ inches long, 



capitatum. 

 Pods pubescent, but the pubescence not black or velvety. 

 Pubescence dense, erect or nearly so, not appressed. 



Seeds dull black with faint rusty markings; pubescence of pods tawny, utile. 



Seeds ash colored; pubescence of pods whitish cinereum. 



Pubescence white, appressed. 



Flowers white; leaf surface undulate; seeds ash colored niveum. 



Flowers purple; leaf surface plane. 



Pod valves with the principal ridge prominent, but secondary ridges 

 rarely more than one. 



Pubescence on pods rather coarse and long; leaflets 3 to 5 inches 



long, rather thick; seeds ash colored hassjoo. 



Pubescence very fine; leaflets larger and thinner; seeds shining 



black aterrimum. 



Pod valves with a well-developed principal ridge and two or more sec- 

 ondary ridges; pubescence soft. 

 Seeds flattened, white with black or gray spots; pods large, very 

 fleshy when green, 5 to 7 inches long; valves with 3 to 5 secondary 



ridges; pubescence very sparse pachylobium. 



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