POACEAE 121 



usually dense and interrupted : spikelets much crowded, the empty scales acuminate, 4—6 



mm. long, including the awn, the flowering scale A-ff ^^ long, acuminate, the strongly 



scabrous midnerve excurrent as a short point. [M. glomerata Trin.] 



In wet places, Xewfoundland to British Columbia, Xew Jersey, North Carolina, Missouri, and 

 New Mexico. Summer and fall. 



4. Muhlenbergia sylvdtica Torr. Stems 3-9 dm. tall, erect, branched : leaf-blades 



5-18 cm. long, 2-6 mm. wide, rougli : panicle 7-lS cm. long, somewhat lax : empty scales 



of the spikelet 2.5-3 mm. long, awn-pointed, rough, the third scale equalling or somewhat 



exceeding the outer ones, very rough, attenuate into a slender awn 2-4 times its length. 



In moist woods and along streams. New Brunswick to Ontario, Minnesota, North Carolina, Ten- 

 nessee, Nebraska and the Indian Territory. Summer and fall. 



5. Muhlenbergia tenuiflora (Willd. ) B.S. P. Stems 6-9 dm. tall, erect, slender, 



simple or sparingly braiu'hed : leat'-blades 6-18 cm. long, 2-8 mm. wide, narrowed toward 



the base, acuminate, rougli : jjanicle 1-2.5 dm. long, slender: empty scales of the spikelet 



unequal, o-^ the length of the flowering scale, awn-pointed, rough, the flowering one 



2.5-3 mm. long, rough, bearing an awn 2-4 times its length, [il/. Wildenorii Trin.] 



In rocky woods, Massachusetts to southern Ontaria, Minnesota, Alabama and Texas. Summer 

 and fall. 



6. Muhlenbergia diffusa Willd. Stems 3-9 dm. long, decumbent, or often prostrate 



or creeping and ascending, very slender, difi^"usely branched : leaf-blades 4-9 cm. long, 1-4 



mm. wide, rough : panicle 5-20 cm. long, slender, somewhat lax : empty scales of the 



spikelet minute, the lower one often wanting, the flowering scale, exclusive of the awn, 



al)out 2 mm. long, very rough, especially on the nerves, the awn 1-4 mm. long. 



On dry hills and in woods, Maine and southern Ontario to Minnesota, Florida, Kansas and 

 Texas. Summer and fall. 



7. Muhlenbergia trichopodes ( Ell. ) Chapm. Stems tufted, wiry, 7-10 dm. tall : 

 leaf-blades long and narrow, stifl' often involute when dry : panicle 2-4 dm. long, its 

 branches erect: spikelets, exclusive of the awn, 3.5-4.5 mm. long, the empty scales 

 acuminate, shorter than the flowering scale, sometimes awn-pointed, the flowering one 

 bearing a short awn 2 mm. long or less. 



In pine lands, North Carolina to Florida and Texas. Summer and fall. 



8. Muhlenbergia capillaris (Lam. ) Trin. Stems erect, wiry, tufted, 5-12 dm. tall : 

 leaf-blades long and narrow, often involute when dry, 1-3 mm. wide : panicle 1.5-4 dm. 

 long, its branches spreading or ascending : spikelets, exclusive of the awn, 3.5-4 mm. long, 

 lanceolate, acuminate, the empty scales usually i as long as the spikelet or less, commonly 

 bearing a short awn, the flowering scale bearing an awn longer than its body, sometimes 2 

 cm. long. [il/. caespitosa Chapm.] 



In dry soil and pine lands, ISIassachusetts, New Jersey and Missouri to Florida, the Indian Terri- 

 tory and Texas. Also in Cuba. Fall. 



9. Muhlenbergia filipes M. A. Curtis. Stems tufted, erect, wiry, 5-10 dm. tall : 

 leaf-blades long and narrow, involute, at least when dry, 1-2 mm. wide : panicle 2-3 dm. 

 long, often included at the base, its long branches spreading or ascending : spikelets, ex- 

 clusive of the awns, 4-5 mm. long, lanceolate, acuminate, the empty scales I as long as the 

 spikelet or less, bearing a long awn, that on the second scale, and also often that on the first, 

 frequently much exceeding the spikelet. 



In sands on the seashore and in pine lands. North Carolina to Florida and Mississippi. Fall. 



10. Muhlenbergia Porteri Scribn. Stems 2-6 dm. long, much branched and pros- 

 trate : leaf-blades 3-6 cm. long, 1-2 mm. wide, flat, acuminate, linear : panicles 8-10 cm. 

 long, the branches widely spreading, rather stiff: spikelets, exclusive of the awn, 3-4 mm. 

 long, the empty scales acuminate, shorter than the spikelet, the flowering one bearing an 

 awn 5-10 nuu. long. 



On hills and plains, central Texas to southern California. Summer and fall. 



56. BRACHYELYTRUM Beauv. 

 Tall perennial grasses, with rather broad flat leaf-blades and a terminal narrow panicle, 

 its branches few, erect and filiform. Spikelets l-flowered, narrow, the rachilla produced 

 beyond the flower into a long glabrous stipe which sometimes bears a small scale at its 

 apex. Scales 3 (or rarely 4), the 2 outer empty, persistent, very small, the first minute, 

 sometimes almost wanting, the third scale elongated, rather rigid, acuminate into a long 

 erect awn and enclosing a somewhat short dorsally sulcate 2-nerved palet of similar texture 

 and a perfect flower, a fourth scale sometimes terminating the rachilla-prolongation. 

 Stamens 2. Styles short, distinct. Stigmas elongated, plumose. 



