THE GENERAL CHARACTERS OF SEEDS 



471 





* 9 



Figure 339A 



a b 



Figure 339B 



I'ls. 339. Ai Self-heal (Prunella vulgaris). A, a group of seeds, enlarged, the 

 lower left-hand one with the scar-appendage broken away ; the upper left- 

 hand one showing the outer face. B, a group showing the natural size ; C, 

 a longitudinal section of a seed, showing the embryo. 



E Motherwort (Leonurus carMaca). a and b, different views of seed, c, seed, 



natural size. 



(After Hillman, A, Bull. Nev. Agr. Bxp. Sta. ; B, Bull. Mich. Agr. Elxp. Sta.) 



SOLANACBAE, NIGHTSHADE FAMILY. 



Horse Nettle (Solanum carolinense L.). 



Berry orange-yellow, 1.6 to 2. cm. in diameter; seeds pale dull 

 yellow, much flattened, obovate, 2 to 3 mm. in length ; finely granu- 

 lar, or indented over whole surface. 



Black Nightshade {Solamum nigrum, L.). 



Berries black, globular, smooth; seed asymmetri'cally ovate, flat- 

 tened, pale yellowish brown, finely granular; diameter about 

 1.5 mm. 



Buffalo Bur {Solanum rostratum Dunal.). 



Black berry enclosed in spiny yellow calyx ; seeds nearly circular, 

 bearing a dent on one side of the margin; fiattened, pitted on the 

 surface; both sides irregularly indented with depressions; color, 

 dull dark brown ; seed about 2.& mm. broad. 



Jimson "Weed {Datura stramonium L.). 



Seed one-eighth in. in length, brownish or blackish, kidney-shaped, 

 elliptical or nearly spherical, with numerous large depressions and 

 smaller pits; hilum with a small depression. 



