n8 



GRAMINEAE. 



Vol. I. 



6. Andropogon furcatus Muhl. Forked 

 Beard-grass. Fig. 269. 



Andropogon furcatus Muhl. ; Willd. Sp. PI. 4:919. _ 1806. 

 Andropogon provincialis subvar. furcatus Hack, in DC. 

 Mon. Phan. 5: 442. 1889. 



Culms erect, stout, smooth and glabrous, 3°-6" 

 tall, simple at base, branched above. Leaves gla- 

 brous or hirsute; blades smooth or rough, 6'-i8' 

 long, 2"-j" wide, acuminate; racemes 2-6, in pairs 

 or approximate at the summit, 2-5' long; joints 

 of rachis and pedicels ciliate with short hairs ; outer- 

 most scale of sessile spikelet 3i"-S" long, twice the 

 length of the rachis-joints, scabrous; awn si"-'/' 

 long, perfect ; pedicelled spikelet consisting of 4 

 scales. 



In dry or moist soil. Maine to Assiniboia, south to 

 Florida and Texas and northern Mexico. Aug.-Sept. 

 Broom-grass, Big Blue-stem, Blue-joint. 



7. Andropogon chrysocomus Nash. Yel- 

 low-haired Beard-grass. Fig. 270. 



Andropogon chrysocomus Nash, in Britton, Man, 70. 

 1901. 



A tall usually stout grass, with extravaginal 

 innovations. Culms 2°-S° tall, the branches in 

 i's-3's ; sheaths smooth and glabrous ; blades up 

 to 1° long, 3J" wide or less, smooth beneath, a 

 little roughened above; racemes in 2's-4's, 2'-3i' 

 long, stout, long-exserted, the hairs of the inter- 

 nodes and pedicels ii"-2" long, usually yellow ; 

 sessile spikelets 4"-s" long, lanceolate, barbed at 

 the base with hairs about I" long, the first scale 

 hispid on the keels, the intercarinal space canalicu- 

 late-depressed and hispidulous toward the apex, 

 the fourth scale bearing a perfect geniculate awn 

 S"-6" long; pedicellate spikelets equalling the 

 sessile ones, awnless. 



In dry usually sandy places, Nebraska and Colo- 

 rado to Texas. Summer and fall. 



8. Andropogon Hallii Hack. Hall's Beard-grass. Fig. 271. 



Andropogon Hallii Hack. Sitz. Akad. Wiss. Wien, 89: 127. 



1884. 

 Andropogon geminatus Hack. ; Beal, Grasses N. A. 2 : 55. 



1896. 



Stems from a creeping rootstock, 3°-6° tall, simple 

 at base, branched above, smooth, more or less glaucous; 

 leaves glaucous; blades i° or' less long, z"-$" wide, 

 smooth; racemes 2 or 3, 1/-4' long, the lateral ones often 

 included in the spathes; joints of rachis and pedicels 

 pubescent with spreading silky white or yellow hairs of 

 about their own length ; outermost scale of sessile spike- 

 let 4"-6" long, acuminate, glabrous at base, from 

 sparingly to copiously silky-pubescent toward the apex, 

 awnless or with a glabrous imperfect awn shorter than 

 the scale ; pedicellate spikelet consisting of 4 scales, the 

 outermost generally larger than the corresponding scale 

 of the sessile spikelet and subtending a palet and three 

 stamens. 



Dry sandy soil, North Dakota and Wyoming to Texas 

 and Arizona. Aug.-Sept. Turkey-foot Grass. 



