VEGETATIVE ORGANS OF GRASSES 



361 



coarse, scabrous, four to eig'ht mm. wide, glaucous. Sheaths 

 compressed, coarsely nerved. Brown scales are numerous, com- 

 ing' from the base of the culms. Ligule ciliate, forming a fringe 

 of hairs. Collar light green to yellow, conspicuous on the inside. 



Sporoholus cuspidatus. Prairie Rush Grass. Figure 141. 



Long resting period. Rhizome creeping. Buds appear at al- 

 most every node, also an abundance of very long, coarse, fibrous 

 roots. Nodes conspicuous. 



''ig. 137. — Poa compressa. Canada Blue Grass. A, ligule; B, first shoot 

 and buds at node of old rhizome ; C, node ; D, old rhizome. 



Sporoholus longifolius. Long Leaved Rush Grass. Figure 

 142. 



Buds of rhizome arise in clusters. 



Stipa spartea. Porcupine Grass. Figure 143. 



An erect perennial. Resting period four months. Rhizomes 

 creeping, the branching rootstocks of the main basal rhizome 

 die the followang year, while new rhizomes grow out and their 

 terminal buds send up new shoots. The new rhizome extends 

 in one direction only. The most vigorous growth takes place at 

 the base of the old rhizome. Roots arising at nodes are rather 

 short, stout, with many root hairs. Leaves folded in bud. Blades 



