466 



WEED FLORA OF IOWA 



BORAGINACEAE, BORAGE FAMILY. 



Common Hound's Tongue {Cynoglossum officinale L,). 



Ovary dividing into 4 achenes, each 5-7 mm. in length, ovate to 

 round, flattened; lower side bearing large ovate scar; surface cov- 

 ered with straight, stiff, barbed prickles. 



Fig. 330. 



Common Hound's Tongue (Cynoglossum officinale), a, b, views of 

 different faces of seed ; c, natural size. 

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



Wild Comfrey (Cynoglossum boreale Fernald.). 



Nutlets convex on the upper face, somewhat triangular, one- 

 seventh in. in diameter, bearing short barbed prickles on convex 

 surface ; color brown. 



Fig. 331. Wild Comfrey (Cynoglossum boreale). 

 (Drawing by Ada Hayden.) 



Stickseed (Lappula echinata Gilibert). 



Ovary separating into 4 achenes, 2.5 mm. long, slightly flattened 

 from ovate, under surface tuberculate, bearing straight ridge from 

 point to middle ; on the upper side, the margins bear a double row 

 of slender barbed prickles. 



Beggar's Lice (Lappula virginiana (L.) Greene). 



Achenes 3 mm. long, borne in clusters of 4, broadly ovate, flat- 

 tened on outer side; the outer surface bearing short stiff barbed 

 prickles, the inner side cone shaped, free from hairs, and bearing 

 a triangular scar. 



