THE GENERAL CHARACTERS OF SEEDS 



447 



Figure 297B 



Fig. 297. A. Tumbling Mustard (Sisymbrium altissimum) . A, a group of 

 seeds indicating the usual forms ; a, one showing the hairy appearance due 

 to the mucilage, either when wet or after drying. B, several seeds, natural 

 size. 



B. Hedge Mustard (Sisymbrium officinale). A, a group of seeds showing the 

 prevailing forms ; a, one showing the fine hairlike mucilage as it appears 

 when wet or after drying. B, group showing the natural size. 

 (After Hillman, Bull. Mich. Agr. Exp. Sta.) 



Marsh Cress {Badicula paXustris (L.) Moench.). 



Pod ovoid; seed pale reddish brown, oval, finely reticulated, 

 length about .6 2-3 nun. ; scar near one end, occupying a deep 

 notch in the contour of the margin. 



Fig. 298. Marsh Cress (Radicula palustris). 

 (Drawing by Ada Hayden.) 



Winter Cress {Barbarea vulgaris R. Br.). 



Seed oblong, flattened, one-sixteenth in. in length ; surface finely 

 reticulated ; the scar ai light-colored appendage at one end ; position 



. : ' ' ^ -:■ 



<s& 



Fig. 299. Winter Cress (Barbarea vulgaris). A, various forms of seeds. B, 

 seed in cross section. C. seeds, natural size. 

 (After Hillman, Bull. Mich. Agr. Exp. Sta.) 



