DESCRIPTIVE MANUAL 



303 



Chemical Composition. — The chemical composition of rib grass, 

 grown in New Hampshire, according to Eept. U. S. Dept. Agr., 

 1879,, p. 121, is as follows:* 



FRESH OR AIR DRY MATERIAL. 



Prairie Plantain {Plantago pursMi R. & S.). 



Description. — A silky, green annual with slender scapes; leaves 

 linear, acute, with marginal petioles; spikes usually cylindrical, 

 villous with rigid bracts ; flowers of two kinds on different plants ; 

 most of them cleistogamous ; sepals oblong, obtuse; corolla lobes 

 broadly ovate; stamens 4; capsule oblong, obtuse, eircumseissile at 

 about the middle ; seeds convex on the back, deeply concave on the 

 face. 



Distribution. — Common westward from Ontario and Illinois to 

 British Columbia, Texas and Mexico. Sometimes a troublesome 

 weed in Missouri and Nebraska. Found along railways in Iowa. 



Extermination. — ^.This little plantain is not likely to give much 

 trouble unless the seeds are able to retain their vitality for a con- 

 siderable length of time. The plant is easily destroyed by culti- 

 vation. 



•Jenkins and Winton. Bull. Off. Exp. Sta. 11 :79. 



