HOW TO KNOW THE GRASSES 



17a. Spikelets hairy, variously colored 18 



17b. Spikelets whitish, glabrous. Fig. 54. 



Tridens albescens (Vasey) Woot. and Stand. 



Perennial; tufted or rarely with rhizomes; 

 culms 30 — 80 cm. tall; panicles spikelike; 

 leaf blades elongated, 2 — 4 mm. wide, 

 sometimes inrolled. This species may be 

 confused with species of Eragrostis, but 

 the fact that the lemma is split at the tip 

 excludes it from that genus. The plants 

 often grow in draws and around water 

 holes. They are succulent and make good 

 forage, but are seldom found in dense 

 stands. April — October. Also known as 

 Triodia albescens. 



Figure 54 



18a. Panicle a dense ovoid tuft, 1 — 3 cm. long, containing usually less 

 than 10 spikelets. Fig. 55. 



Tridens pilosus (Buckl.) Hitch. 



Perennial; tufted; 10 — 30 cm. tall. 

 Most of the very narrow white-mar- 

 gined leaves are at the base of the 

 plants. The culm usually consists of a 

 single intemode. The plants are very 

 shallow rooted and easily pulled up. 

 Found frequently on thin rocky soils 

 and overgrazed ranges of the South- 

 west. This species has Httle forage 

 value and is generally regarded as an 

 indicator of overgrazing. March — Oc- 

 tober. Also known as Triodia pilosa. 



Figure 55 



30 



