14 THE SOY BEAN ; HISTOEY, VARIETIES, AND FIELD STUDIES. 



otherwise resembling each other very closely. Two strains of this 

 sort can, however, be readily separated. Roxburgh (Catalogue, p. 55) 

 and Voigt (Hortus Suburbanus Calcuttensis, p. 231) each describe a 

 variety with white seeds and yellow flowers. Such may really exist, 

 but there is no hint of yellow flowers in the 290 varieties we have 



studied. 



Most soy-bean flowers have no perceptible odor; but Nos. 23336, 

 23337, and 20797, when in full flower at Jackson, Tenn., September 

 13, 1909, were very fragrant, the odor suggesting that of lilacs. 



The flowers are borne on short axiflary racemes, commonly with 

 8 to 16 in each cluster. In some varieties, however, the racemes may 

 have as many as 35 flowers. 



PODS. 



In most varieties of soy beans the pods are distinctly compressed, 

 but in some cases cylindric, and all possible intermediate forms exist. 

 (See Pis. VI and VII.) The number of seeds per pod in most varieties 

 is 2 to 3. In a few sorts, however, the number is 3 to 4. Wein 

 (Journal fur Landwirtschaft, 1881, Supplement (Ergiinzungshaf t) , 

 p. 3) speaks of varieties having occasionally 4 to 5 seeds in a pod, but 

 we have never seen but one example of a 5-seeded pod. The largest 

 pods are perhaps those of No. 23213, 2| to 3 inches long; the smallest, 

 those of No. 17256, three-fourths inch to f^ inches long. 



Many soy-bean varieties shatter their seeds easily. In general, 

 small pods shatter less easily than large pods, but there are exceptions 

 in each case. Among the varieties tested the Peking, No. 17852B, 

 holds its seeds far better than any other. Plates IV and V show 

 the striking differences in this regard. 



Soy-bean pods are commonly borne in clusters of 3 to 5. In a few 

 varieties the clusters may contain 12 pods. Depending on the length 

 of the internodes, the pods appear crowded or scattered. A single 

 plant may bear over 400 pods. The color of the pods may be gray 

 or tawny, or rarely black. Gray pods bear white or grayish hairs, 

 while all tawny pods have tawny pubescence. Certain varieties with 

 black pods bear white or grayish hairs. 



SEEDS. 



The range in size and shape of soy-bean seeds according to variety 

 is well shown in Plate VIII. None are truly globose, but this 

 shape is closely approximated by some varieties. Others are much 

 flattened. The great majority, however, are elliptic in outline, the 

 thickness less than "the breadth. 



Most varieties of soy beans have unicolored seeds in the following 

 colors, straw-yellow, olive-yellow, olive, green, brown, and black, the 

 last really a dark violet. Straw-yellow seeds are in some varieties 



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