GRAMINEAE (GRASS FAMILY) 71 



8. Poa reflexa Vasey and Scribn. Contrib. U. S. Nat. Herb. 1: 276. 1893. 

 Culms 2-4 dm. high, slender, erect, smooth: leaves of the culm about 3, mostly 

 narrow, acute, 5-8 cm. long: sheaths long, smooth; ligule obtuse, about 2 mm. 

 long: panicle pyramidal, 5-10 cm. long, with about 6 nodes; the branches 

 capillary, rather distant, the lower ones 5-8 cm. long, smooth, spreading and 

 becoming reflexed, spikelet-bearing near the end: spikelets 2-3-flowered, 

 3-4 mm. long: glumes acute, smooth; lemma ovate-lanceolate, acute, ob- 

 scurely nerved, pubescent on the nerves and at the base ; palet pubescent on 

 the keels. (P. acuminata Scribn. Beal's N. Am. Gr. 2: 538. 1896; P. pudica 

 Rydb. Bull. Torr. Bot. Club 32: 603. 1905.) Wet sandy soils, at middle or 

 higher elevations; Montana to New Mexico. 



9. Poa laxa Haenke, Sudet. 118. 1791. Culms 3 dm. tall or less, erect, sim- 

 ple: leaves 2.5-7.5 cm. in length, the branches usually erect, sometimes 

 ascending, 2.5 cm. long or less: spikelets 3-5-flowered, 4-5 mm. long: glumes 

 usually 3-nerved, acute, glabrous, rough on the keel at its apex; lemma 

 3-3.5 mm. long, obtuse, 3-nerved, or sometimes with an additional pair of 

 obscure nerves, the mid-nerve pilose on the lower half, rough above, the lateral 

 ones pilose for one third their length. In the Rocky Mountains and in those 

 of New England and New York; infrequent in our range. 



10. Poa alpina L. Sp. PI. 67. 1753. Smooth arid glabrous: culms 1-4.5 dm. 

 tall: ligule 2 mm. long, truncate; leaves 2.5-7.5 cm. long, 2-4 mm. wide, 

 abruptly acute: panicle 2.5-7.5 cm. in length, the branches generally widely 

 spreading, 2.5 cm. long or less: spikelets 3-5-flowered, 5-6 mm. long: glumes 

 broad, glabrous, rough on the keel, acute; lemma about 4 mm. long, obtuse, 

 pilose for half the length, pubescent between the nerves toward the base. 

 Frequent in the mountains and extending northward and eastward. 



11. Poa Pattersonii Vasey, 1. c. 275. Culms low, densely tufted, 15-25 cm. 

 high, slender, naked above: radical leaves numerous, 5-8 cm. long, very nar- 

 row, flat or conduplicate, smooth: panicle dense, weakly erect, or nodding; 

 branches mostly in twos, subappressed : spikelets 4-6 mm. long, 2-3-flowered: 

 glumes nearly as long as the lemma, acute; lemma purplish, acute, 4 mm. 

 long, pubescent on the lateral nerves and below the middle but not webbed 

 at the base; palet pubescent on the keels. (P. rupestris Vasey, a name re- 

 placed by P. rupicola Nash, Mem. N. Y. Bot. Gard. 1: 49. 1900.) Alpine; 

 Colorado and Wyoming. 



12. Poa Lettermannii Vasey, Contrib. Nat. Herb. 1: 273. 1893. Dwarf, 

 densely tufted, 5-10 cm. high: leaves mostly radical, flat, 3-5 cm. long; ligule 

 rather conspicuous, acute ; cauline leaves 1 or 2 : panicle 10-25 mm. long, rather 

 dense; branches mostly in twos, short, erect, with 1-3 spikelets: glumes nearly 

 as long as the spikelets, acute, nearly smooth, 3-4 mm. long; lemma shorter, 

 ovate-oblong, acute, obscurely nerved, smooth; palet 2-toothedat the acumi- 

 nate apex. Alpine summits, Colorado to Washington. 



13. Poa Wheeleri Vasey, Rothr. Rep. 6: 291. 1878. Culms 3-8 dm. high, 

 from running rootstocks: ligules about 2 mm. long; leaves of sterile shoots 

 15-24 cm. long, 2-4 mm. wide, rigid, conduplicate or involute, with a firm 

 oblique point: panicle open, 10-15 cm. long, its slender branches mostly in 

 pairs, the longer about 5 cm. long: spikelets lance-elliptic, .4-6 mm. long, 

 3-flowered: glumes subequal, 3-nerved; lemma oval, subacute, about as long, 

 ciliate on the lateral nerves and below; palet truncate, ciliate on the keel. 

 Frequent in our range and extending to Washington. 



14. Poa nervosa (Hook.) Vasey, 111. N. Am. Gr. 2: 81. 1893. Culms 4-8 

 dm. high, rather slender, smooth: radical leaves narrowly linear, 15-25 cm. 

 long; those of the culms about 3, rather distant, erect, flat, 3-8 cm. long, 

 2-4 mm. wide: panicle 5-12 cm. long, branches ^spreading, the lower 2-5 

 together, filiform, naked below, few-flowered near the ends: spikelets 3-8- 

 flowered, 4-5 mm. long: lemma linear-lanceolate, strongly 5-nerved, minutely 

 scabrous on the nerves; palet and lemma subequal. [P. Traceyi Vasey, 

 Contrib. U. S. Nat. Herb. 1: 276. 1893; P. flexuosa occidentalis Vasey; P. 

 occidentalis (Vasey) Rydb.; P. callichroa Rydb. Bull. Torr. Bot. Club 32: 603. 

 1905.] Idaho and Montana to Colorado, 



