HOW TO KNOW THE GRASSES 



115a. Lemmas greenish-yellow, thin, with prominent intermediate 

 nerves; sheaths usually scaberulous. Fig. 149. 



ROUGH STALK BLUEGRASS; TRIVIALIS Poa trivialis L. 



Perennial; tufted; culms 30 — 100 cm. tall, 

 often somewhat bent or reclining at the base; 

 panicles open, ovoid or pyramidal, the spike- 

 lets clustered near the outer ends of the 

 branches; lemmas glabrous or hairy on the 

 lateral nerves. The plants are often found 

 growing wild in wet places, and the seed 

 is planted in lawn mixtures for shady places. 

 May — June. Introduced from Europe. 



Figure 149 



115b. Lemmas green, usually purple or bronzy at the tip, the inter- 

 mediate nerves inconspicuous; sheaths smooth. Fig. 150. 



Poa palustris L. 



Perennial; plants slender, weak, with bent 

 and recHning (decumbent) culm bases; pani- 

 cles open, pyramidal, with slender, weak 

 branches. The lemmas are usually purple 

 and golden banded near the tip, making 

 them very attractive under the lens. Wet 

 meadows, stream banks, and moist woods; 

 seldom numerous in one place. June — August. 

 This species is native to both North America 

 and Eurasia. 



Poa inferior Rydb. is very similar to the 

 above, but has erect, tufted culms, small pani- 

 cles less than 10 cm. long, and short ligules 

 usually 1 mm. long or shorter. Across Cana- 

 da and south to northern New England, Wis- 

 consin, North Dakota and the high plains 



Figure 150 



and western mountain states. 



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