IOO FLORA. 



glabrous. Leaves 5-12.5 cm. long, 2-6 mm. wide, scabrous; panicle 5-11.25 cm. 

 in Length, usually dense and interrupted, the brandies 1.25-2.5 cm. long, erector 

 appressed, the spikelets much crowded; outer scales of the spikelet acuminate, 4 

 mm. long, including the awn, smooth, or scabrous, especially on the keel; third 

 scale one-half to two-thirds as Long, acuminate, the strongly scabrous midrib 

 excurrent in a short point. In wet places, Newf. to Br. Col., south to N. J., Mo. 

 and X. Mex. Aug. -Sept (M. glomcrata Trim) 



4. Muhlenbergia sylvatica Torr. Wood Muhlenbergia. (I. F. f. 323. 

 Culms 3-9 dm. tall, erect, branched. Leaves 5-17.5 cm. long, 2-6 mm. wide, 

 rough; panicle 7.5— 17.5 cm. in length, somewhat lax, the branches 2.5-7.5 cm. 

 Long, erect or ascending; outer scales of the spikelet2,5-3 mm. long, awn-pointed, 

 scabrous ; third scale equalling or somewhat exceeding the outer ones, strongly 

 scabrous, attenuate into a slender awn 2-4 times its length. In moist woods and 

 along streams, N. B. to Out. and Minn., south to N. Car., Tenm, Neb. and the Ind. 

 Terr. Aug. -Sept. 



5. Muhlenbergia ambigua Torr. Minnesota Muhlenbergia. (I. F. f. 

 324.) Glabrous; culms 3 dm. tall or lower, erect, branched, smooth. Sheaths 

 shorter than the internodes; leaves 2.5-7.5 cm. long, 2-4 mm. wide, scabrous; 

 panicle 2.5-7.5 cm. long, rigid, its branches 1.25-2.5 cm. long, dense, appressed; 

 outer scales of the spikelet awn-pointed, unequal, the longer about 4 mm. in length 

 and exceeding the body of the third scale, which is scabrous, villous, and attenuate 

 into an awn 2-3 times its length; a fourth narrow awned scale is nearly always 

 present. Along a lake shore in Minn. 



6. Muhlenbergia comata (Thurb.) Benth. Hairy Muhlenbergia. (I. F. f. 

 325.) Culms 3-7.5 dm. tall, erect, slender, smooth and glabrous. Sheaths shorter 

 than the internodes, smooth or slightly scabrous; leaves 6.2-12.5 cm. long, 2-4 mm. 

 wide, erect, flat, rough ; panicle often tinged with purple, 5-10 cm. in length, dense, 

 branches 1.25-3.75 cm. long, erect; outer scales of the spikelet equal, or the sec- 

 ond a little the longer, smooth, scabrous on the keel; third scale shorter, smooth 

 and glabrous, bearing an awn 2-3 times its length, the basal hairs silky, erect, 

 fully as long as the scale. On prairies, Kans. (?) and Colo, to Cal. Aug. -Sept. 



'7. Muhlenbergia tenuiflora (Willd.) B. S. P. Slender Muhlenbergia. 

 (I. F. f. 326.) Culms 6-9 dm. tall, erect, slender, simple or sparingly branched, 

 smooth. Sheaths usually shorter than the internodes ; leaves 6. 25-17. 5 cm. long, 

 2-8 mm. wide, narrowed toward the base, acuminate, scabrous; panicle 1.25-2.25 

 dm. long, slender, its branches 2.5-8.75 cm. long, appressed; outer scales of the 

 spikelet unequal, half to two-thirds the length of the third one, awn-pointed, sca- 

 brous; third scale 2.5-3 mm. long, scabrous, bearing an awn 2-4 times its length. 

 In rocky woods, Mass. to southern Ont. and Minn., south to Ala. and Tex. Aug.- 

 Sept. 



8. Muhlenbergia diffusa Willd. Nimble Will. Dropseed-grass. (I. F. 

 f. 327.) Culms 3-9 dm. long, decumbent, or often prostrate or creeping and as- 

 cending, very slender, diffusely branched. Sheaths shorter than the internodes, 

 loose; leaves 3.75-8.75 cm. long, 1-4 mm. wide, scabrous; panicle 5-20 cm. long, 

 slender, somewhat lax, its branches 2.5-5 cm - l° n g> erect, outer scales of the spike- 

 let minute, the lower one often wanting ; the third scale, exclusive of the awn, about 

 2 mm. long, strongly scabrous, particularly upon the nerves; the awn 1-4 mm. in 

 length. On dry hills and in woods, Me. and southern Ont. to Minn., south to 

 Fla., Kans. and Tex. Aug. -Sept. 



9. Muhlenbergia palustris Scribn. Swamp Muhlenbergia. Culms slen- 

 der, weak, 6-10 dm. long. Sheaths smooth and glabrous; leaves erect, 3-5 cm. 

 long, about 2 mm. wide, smooth beneath and rough above; panicle slender, con- 

 tracted, I-I.5 dm. long, its branches appressed; spikelets, exclusive of the awn, 

 2.5-2.8 mm. long, the first scale shorter than the second, which is about one-third 

 as long as the spikelet; the flowering scale 2.3-2.5 mm. long, shortly 2-toothed at 

 the apex, bearing an awn between the teeth 5.5-8 mm. long, the callus hairy. In 

 a swamp at Washington, D. C. Sept. 



10. Muhlenbergia microsperma (DC.) Trim SMALL-SEEDED Muhlenbem 

 01 \. (I. F f . 328.) Culms 1.5-4.5 dm. tall, erect, finally decumbent or somewdiat 

 prostrate at base, slender, diffusely branched. leaves 1.25-6.25 cm. long, 2 m 

 wide or less, scabrous; panicle 5-10 cm. in length, slender, open, the branches 2. 



5 



