THE GENERAL CHARACTERS OF SEEDS 



435 



Fig. 271. Rough Pigweed (,Ainaranthu3 retroflexus) . A, seeds; B, one having 



the seed-coat broken ; C, the natural size. 



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



Water Hemp {Acnida fuberculata ^loq.). 



Seeds erect, lens-shaped, one-fifteenth in. in diameter, smootli, 

 bhining. black, 2-5 remnants of stigmas, sometimes ^vith the at- 



FiG. 275. "Water Hemp (.Acnida tuberculata) . a, b, e, different views of seed; 



d, cross section ; e, in seed envelope ; f, natural size, 



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



tached calyx and mucronate bracts; utricle longer than bracts; 

 ciremnscissile, not angled. In seed of clover and alsike. 



CARYOPHYLLACEAE, PINK FAMILY. 



Chickweed {Stellaria media (L.) Cyrill.). 



Kidney-shaped, broadly egg-shaped, to wedge-shaped, one- 

 twentieth in. in length, finely and closely tubercled; color grayish 



Fig. 276. Chickweed IStellaria media'). A, seeds, side view. B, one shown 

 in edge view. C, a sectional view showing the embryo and endosperm. 

 D, group showing the natural size. 



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



to light brown ; scar marked by a longitudinal groove at basal end. 

 Occasionally found in clover. 



