472 



WEED FLORA OF IOWA 



Figure 3400 



Fro. 340. A. Horse Nettle (Solanum. carolinense) . a, b, c and d, different 

 views of seed ; e, fruit. 



B. Black Nightshade (Solanum nigrum"), a, two seeds, side view, enlarged; h, 

 group showing the natural size ; c, a section of a seed, parallel with the 

 faces, showing the spirally curved embryo imbedded in the endosperm. 



C. Buffalo Bur (Solanum rostratum). a, prickly calyic ; b, seeds with pits; c, 



' seed, natural size; d, cross section of seed with embryo. 



D. Jimson Weed (Datura stramonium), a. and b, seeds from different views; 

 between a and b, seeds, natural size ; c, cross section of seed showing 

 embryo. 



(After Hillman, A, C, D, Mich. Agr. Exp. Sta. Bull; B, Bull. Nev. Agr. Exp. Sta.) 



SCROPHULARIACBAE, FIGWORT FAMILY. 



Moth MiiUein {Verbasawm blattaria L.). 



Seeds light to dark brown, 0.5 to 1 mm. in length, prismatic, 

 6-sided, base truncate, broader than the rounded apex; each side 

 face pitted in longitudinal rows. 



Mullein {Veriascum thapsus L.). 



Seeds eoliiiiiiiBr, 4-6-sided, top usually truncate, base nearly so ; 

 one-thirtieth in. in length ; faces deeply transversely pitted ; surface 

 duU; color brown; scar in middle of flattened base. Reported as 

 frequently found in seeds of timothy and similar grasses. 



