4 BULLETIN 119, U. S. DEPARTMENT OF AGRICULTURE. 



radiatus, from both, of which, it differs greatly. The adsuki is prob- 

 ably native either in Japan or in Chosen, but the plant is not defi- 

 nitely known in a wild state. 



DESCRIPTION. 



The adsuki bean is a summer annual, requiring essentially the same 

 conditions of climate as the common bean. 



The plants are bushy in habit, growing from 1 to 2| feet high, 

 according to variety and soil. The earlier varieties are strictly 

 bushy in habit and mostly erect, while the later ones are slightly viny 

 at the tips of the stems and branches, and some of them are decum- 

 bent. As with other annual legumes, the later varieties are larger 

 than the early ones. The whole herbage is somewhat hairy, and the 

 leaves persist until the pods are fully mature. The flowers are bright 

 yellow, 6 to 12 in a cluster. 



The varieties are very numerous, at least 60 distinct sorts having 

 been tested at Arlington farm, and among these as strays or, more 

 likely, natural hybrids nearly as many others have been detected. 



The varieties are distinguished mainly by the period of maturity 

 and the color of the pods and seeds. 



At Arlington farm the earliest varieties are fully mature in three 

 months, while the latest require five months. 



The pods are straw colored in most varieties, brown in a few, and 

 blackish in a considerable number. In size the pods vary with the 

 seeds, the largest pods being 5 inches long, the smallest 2.5 inches. 



Each pod bears normally 8 to 10 seeds. The pods do not shatter 

 readily, but as they are thin the beans may germinate in the pods 

 in long-continued wet weather. 



The seeds are subcylindric or but slightly compressed, subtruncate 

 at the ends, and but slightly longer than broad. The following colors 

 occur in the order of their frequency: Maroon, straw to nearly white, 

 gray (really black speckled on a greenish yellow ground color), 

 maroon and straw, black, brown, blue-black, and straw. 



The embryo in all cases is nearly white and brittle in consistency. 



The adsuki bean is self-fertile, pods setting perfectly where the 

 flowers are bagged. It forms natural hybrids readily, more so appar- 

 ently than any other related species. In a number of cases the seed 

 of a single plant grown in a row produced diverse progeny. Thus 80 

 plants were grown from the seed of a plant of S. P. I. No. 19988, 

 which had blackish pods and brown seeds. Of these 80 plants 16 had 

 maroon seeds, 8 with straw-colored and 8 with blackish pods; 53 

 had brown seeds, 17 with straw-colored and 36 with blackish pods; 

 and 11 had buff seeds, 4 with brown and 7 with blackish pods. It is 

 probably due to this ease of hybridizing that the varieties of adsuki 

 beans are so numerous, and where they are grown near together new 

 sorts will constantly appear. 



