Oct. i 5l 1920 Mustard Seeds and Substitutes: I. Chinese Colza 125 



long and 2 inches across when the flowers are open, subsequently elonga- 

 ting into racemes 6 to 18 inches long, with pedicels % to 2>£ inches long 

 in the extreme, slender, and without bracts or bractlets. The long pedi- 

 cel particularly distinguishes the flower from the flowers of the mustards, 

 which rarely have pedicels longer than K inch (17). Otherwise the flowers 

 do not differ essentially from the general type of the genus Brassica. 



The mature fruit pods (PI. 18, B) are 2-valved, and are 2 to 3 inches 

 long, including the beak. The beak of the pod is rather thickly conical 

 and from 0.4 to 0.8 inch long. The valves are convex, rigidly leathery, 

 rather finely nerved, and beaded opposite the seeds. A cross section 

 of the pod is broadly elliptical throughout the entire length and about 

 % inch thick across the long axis. In some of the pods both yellow and 

 brown seeds have been observed, giving evidence that the yellow and 

 brown seeds are only variations in the same kind of seed. An examina- 

 tion of plants grown from brown and yellow seed will also prove this 

 statement to be correct (PI. 12, A). The green seeds are immature, as is 

 indicated by the abundance of small spherical starch grains occurring 

 in the cotyledons. From 8 to 12 seeds are found under each valve of a 

 fully developed fruit pod. 



BOTANICAL CONCLUSIONS 



On the basis of the descriptive data given, the authors' material must 

 be classified with the colzas and rapes rather than with the true mustards. 

 While some of the characteristics observed would have only a limited 

 diagnostic value if taken alone, they serve as additional means for the 

 differentiation. Considered together, they make the proper classification 

 the more certain. The botanical characteristics may be briefly recapit- 

 ulated as follows. 



SEEDS 



1. As is typical of the colza group, the seeds are rather smooth. True 

 mustards, except Sinapis alba 1,., show generally a more pronounced 

 reticulation of the seed coat. 



2. As in the case of Indian colza (Brassica campestris var. glauca), the 

 seeds are more or less flat. True mustards are generally spherical, except 

 Brassica besseriana Andrews, which has large brown seeds of more or less 

 oval shape. Many rapes and Brassicas other than mustard, however, are 

 also spherical. 



3. A very pronounced ridge can be found in almost every seed of the 

 Chinese and Indian colza, while it is scarcely developed in the mustard 

 seeds, with the possible exception of Sinapis alba. 



4. The swelling and polarizing epidermis is lacking in the Chinese 

 colza seed, as usually also in other seeds of the colza group. While not 

 so distinct or appreciable in certain forms or variaties of Brassica juncea, 

 the swelling of the mucilaginous epidermis and the polarization are 



