41 



the seed varies from dark, shiny brown to black and has no trans- 

 verse depression. The cotyledons are right and left of the per- 

 pendicular axis of the seed. The surface of this variety is smooth, 

 and has very few mucilage cells in evidence. Fig. 36 shows the 

 rib grass seed and the elements of vise in its diagnosis. 



BRACTED PLANTAIN. 



(Plantago arislata, L.) 



The seeds of this plantain are somewhat larger than those 

 of Plantago lanceolata, but are very similar in shape; i.e., canoe 

 shaped, but are broader and flatter. They vary in length from 

 2 — 32 m.m. and on the concave side are distinctly marked with 

 a concentric ring of light color, enclosing an inner portion of 

 whitish color. The seeds are light brown in color, and the con- 

 vex side which is usually darker in color is marked with a slight 

 transverse depression that is barely distinguishable to the naked 

 eye, but is very easily seen under the hand lens. The surface 

 is covered with mucilage cells which, when swollen with water, 



Figui'e 37 

 Fig. 37. Bracted Plantain. 



are of the "open 8" or hour glass type. The cotyledons are 

 right and left with respect to the central axis, but are broader 

 than those of the rib grass. Fig. 37 shows the bracted plantain 

 and some of its elements. 



