GRAMTNEAE. lOl 



cm. long or less, ascending or erect; outer scales of the spikelet unequal, obtuse or 

 rounded at apex, about one-third the length of the third scale, which is 2.5-3 mm. 

 long, exclusive of the awn, and strongly scabrous; awn 1.2-2.4 cm. in length. In 

 dry soil, Kans. to Cal., south to Mex. 



11. Muhlenbergia capillaris (Lam.) Trin. LONG-AWNED HAIR-GRASS. 

 (I. F. f. 329. j Culms 4.5-12 dm. tall, erect, simple, smooth or nearly so. Sheaths 

 smooth, the lower short and overlapping, the upper ones much longer; leaves 1.5-3 

 dm. long, 2-4 mm. wide, scabrous; panicle 1.75-3 dm. in length or more, diffuse, 

 the capillary branches 1-2 dm. long, at length widely spreading; spikelets on long 

 hair-like pedicels which are clavate -thickened at the apex; outer scales unequal, 

 acute or short-awned, slightly scabrous; third scale, exclusive of the awn, 4 

 mm. long, about twice as long as the first one, scabrous, the awn 6-18 mm. in 

 length. In dry sandy or rocky soil, Mass, to N. J. and Mo., south to Fla. and 

 Tex. Panicle usually light purple. Sept.-Oct. 



12. Muhlenbergia gracillima Torr. FILIFORM MUHLENBERGIA. (I. F. f. 

 330.) Culms 1-3.5 dm. ta ^> from a slender creeping rootstock, erect, slender, sim- 

 ple, rigid. Leaves 2.5-5 cm - l n g> involute-setaceous, smooth or somewhat sca- 

 brous, rigid, the basal numerous, usually strongly recurved, the 1-3 culm leaves 

 erect or ascending; panicle 5-22.5 cm. in length, open, the branches finally widely 

 spreading, 2.5-7.5 cm. long, filiform; spikelets alxmt as long as the filiform pedi- 

 cels, which are clavate-thickened at the apex; outer scales unequal, usually awn- 

 pointed or short-awned, slightly scabrous; third scale 2.5-3 mm. long, longer than 

 the outer ones, sometimes twice as long, scabrous ; awn 2-4 mm. long. On prairies, 

 Kans. to Colo., south to Tex. and N. Mex. Sept.-Oct. 



13 Muhlenbergia pungens Thurb. PRAIRIE MUHLENBERGIA. (I. F. f. 

 331.) Culms 1.5-3.75 dm. tall, from a creeping rootstock, erect from a decumbent 

 branching base, rigid, minutely pubescent. Sheaths crowded at the base of the 

 culm, scabrous; leaves 2.5-5 cm - l n g> involute-setaceous, rigid, scabrous; panicle 

 7.5-15 cm. in length, open, the branches 5-6.25 cm. long, single, distant, much di- 

 vided from near the base, the divisions apparently fascicled; spikelets on long ped- 

 icels, which are clavate-thickened at the apex; outer scales, when mature, equalling 

 or often shorter than the body of the third one, scabrous, especially on the keel; 

 thirdvscale, when mature, 1.5-2 mm. long, scabrous, the awn shorter than its body. 

 On prairies, Neb. to Utah, south to Tex. and Ariz. Aug. -Sept. 



32. BRACHYELYTRUM Beauv. 



A tall grass with flat leaves and a narrow panicle. Spikelets I -flowered, nar- 

 row, the rachilla produced beyond the flower, and sometimes bearing a minute scale 

 at the summit. Scales 3; the outer small and inconspicuous, the lower often want- 

 ing; the third much longer, rigid, 5-nerved, acuminate into a long awn; palet 

 scarcely shorter, rigid, sulcate on the back, 2-nerved. Stamens 2. Styles short, 

 distinct. Stigmas plumose, elongated. Grain oblong, free, enclosed in the scale and 

 palet. [Greek, in allusion to the minute outer scales. ] A monotypic genus of east- 

 ern N. Am. 



i. Brachyelytnm erectura (Schreb.) Beauv. BRACHYELYTRUM. (I. F. f. 332.) 

 Culms 3-9 dm. tall, pubescent at and near the nodes. Sheaths more or less villous, 

 especially at the throat; leaves 5-12.5 cm. long, 6 18 mm. wide, scabrous; panicle 

 5-15 cm. in length, slender, branches 2.5-7.5 cm. long, erect or appressed; outer 

 scales of the spikelet unequal, the upper less than one-third as long as the flower- 

 ing scale, the lower minute or wanting; third scale, exclusive of the awn, 9-12 mm. 

 long, scabrous, especially on the midnerve, the awn erect, 1.8-2.4 cm - l n g- Moist 



? laces. Newf to western Ont. and Minn., south to N. Car., Tenn. and Kans. 

 uly-Aug. 



33. HELEOCHLOA Host. 



Perennial tufted grasses with flat leaves and spicate or paniculate inflorescence. 

 Spikelets I -flowered. Scales 3 ; the 2 outer empty, somewhat unequal, membran- 

 ous, acute, ciliate-keeled ; the third scale similar, a little longer ; palet shorter, 

 hyaline, 2-nerved. Stamens 3. Styles distinct. Stigmas plumose. Grain 

 oblong, free, loosely enclosed in the scale. [Greek, signifying meadow-grass.] 



