THE GENERAL CHARACTERS OF SEEDS 



467 



h ^- 



Figure 332B 



Figure 332A 



Fig. 332. A. Stickseed (.Lappula echinata). a, b, views of different faces of 



seed ; c, natural size. 

 B Beggar's Lice (Lappula virginiana) . a, b, views of different faces of seed; c, 



natural size. 

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



Narrow-leaved Pueeoon {Lithospermum angustifolium Michx.). 



Nutlets ovoid, keeled on inner face, one-eigMh in. long; surface 

 smooth., shining, pitted; color white to yellowish white; base irre.p- 

 ular with projecting margin; bearing base with projecting ridges. 



Fig. 333A 



Fig. 333. A Narrow-leaved Puccoon (.lAthospermum angustifolium). 



B. American Gromwell (IAt}U)Spermuni latifolium). 



(Drawings by L. K. Collins). 



American Gromwell {lAthospermum latifolium Michx.). 



Nutlets ovoid to globose, one-sixth in. in diameter, white, shining ; 

 glabrous but prominently pitted ; base oblique. 



Com Gromwell (Lithospermum^ wrvense L.). 



Ovoid nutlets 4 or fewer, convex on back, inner face with distinct 

 ridge ; one-sixteenth to one-twelfth in. in length ; color from whitish 

 to dark brown, surface glabrous, but wrinkled and pitted; base 

 obliquely flattened, bearing the scar. Reported to occur with 

 grain seed. 



