476 



WEED FLORA OF IOWA 



Figure 345A 





~^l m l 





Figure 345B 



Fig. 345. A. Common Plantain (Plantago major), a, a group of seeds, en- 

 larged, showing the relative form and size, also the surface ridges as dark 

 lines ; b, a group showing the natural size ; c, a cross section of a seed. 



B. Plantago rugelii. A, seeds, the upper two showing the scar. B, seed show- 

 ing the mucilage. C, a seed-vessel. D, seeds, natural size. 

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



RUBIACEAE, MADDER FAMILY. 



Cleavers (Galium aparine L.). 



Fruit indehiscent, spherical, one-tenth to one-eighth in. in diam- 

 eter, roughened with prickles, tuberculate when prickles are rubbed 

 off ; color blackish ; embryo curved ; endosperm horny ; fruit covered 

 with hooked trichomes. 



Fig. 346. 



Cleavers, or Bedstraw {Galium aparine). 

 (After Winton.) 



