GENERAL CHARACTER OF THE GENUS STIZOLOBIUM. 



been recognized by botanists. There is also a considerable range 

 as respects the life period of the species, some being much earlier 

 than the Florida velvet bean and others much later. 



The pod differences are displayed in differences of size, of shape, 

 of ridges on the valves, and especially in the character of the pubes- 

 cence. The latter character in the various forms is such that it 

 seems impossible to refer them to a single species, as in no genus of 

 leoumes known to us do we find differences of this kind in agricultural 

 varieties known to be such. Furthermore, these plants never seem 

 to have been cultivated sufficiently to give rise to series of varieties 

 such as are found in most cultivated legumes. A number of the 

 species have been cultivated to a slight extent by the Hindus. An- 

 other species, Stizolobium velutinum (Hassk.) (Mucuna velutina 

 Hassk.), seems to be more or less extensively cultivated in Java. 

 In this species Hasskarl mentions six varieties differing in seed 

 characters, but calls attention to no pod differences. The evidence 

 at hand does not yet justify us in deciding whether all of these are 

 really garden varieties or distinct species, but the latter conclusion 

 best coincides with the facts thus far ascertained. Still another 

 species, Stizolobium hassjoo, is said to be extensively cultivated in 

 Yezo, the north island of Japan. This last is by far the earliest 

 form yet obtained and will doubtless mature its seed as far north as 

 Tennessee and North Carolina. From a single season's experience 

 it seems to possess unusual merit and will probably come into exten- 

 sive cultivation, especially for growing with corn. 



Detailed notes setting forth the present knowledge of the differ- 

 ent forms is given in connection with each species. 



GENERAL CHARACTER OF THE GENUS STIZOLOBIUM. 



All of the stizolobiums thus far grown are large, annual, much- 

 branched, twining herbs, the stems twining in an opposite direction 

 from the hands of a watch; leaves trifoliate, with large membrana- 

 ceous leaflets shorter than the petiole; leaflets ovate, the lateral ones 

 oblique, all mucronate, and attached by short, fleshy, very pubescent 

 petiolules; stipules small and lanceolate; stipels bristle-like; flowers 

 in pendent, usually long racemes, the flowers mostly in groups of 

 three; mature pods black, pubescent, marked with one or more lon- 

 gitudinal ridges, or these rarely obscure or wanting. 



From an economic standpoint, the species of Stizolobium may be 

 divided into two groups, those which have abundant long stinging 

 hairs on the pods and those which have few or no stinging hairs. 

 The former also have stinging hairs on the calyx. In the former 

 category are to be placed Stizolobium pruriens (L.) Medic. (DolicTios 

 pruriens L.), the cowhage or co witch, the type of the genus which is 



179 



