7. Andropogon Chrysocomus Nash. Yellow-Haired Beard-Grass

Fig. 270

Andropogon chrysocomus Nash, in Britton, Man. 70. 1901.

A tall usually stout grass, with extravaginal innovations. Culms 2°-5° tall, the branches in 1's-3's; sheaths smooth and glabrous; blades up to 1° long, 3 1/2" wide or less, smooth beneath, a little roughened above; racemes in 2's-4's, 2'-3 1/2' long, stout, long-exserted, the hairs of the inter-nodes and pedicels 1 1/2"-2" long, usually yellow; sessile spikelets 4"-5" long, lanceolate, barbed at the base with hairs about i" long, the first scale hispid on the keels, the intercarinal space canaliculate-depressed and hispidulous toward the apex, the fourth scale bearing a perfect geniculate awn 5"-6" long; pedicellate spikelets equalling the sessile ones, awnless.

In dry usually sandy places, Nebraska and Colorado 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 1° or less long, 3"-5" 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 spikelet 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.

9. Andropogon Paucipilus Nash. Few-Haired Beard-Grass

Fig. 272

Andropogon paucipilus Nash, in Britton, Man. 70. 1901.

A glabrous perennial. Culms up to 31/2º tall, sparingly branched above; blades erect, firm, usually somewhat glaucous, long-acuminate, the lower 8-12' long and 2 1/2"-3 1/2" wide; racemes in pairs, 2'-3' long, the rachis internodes glabrous, or the margins with a few long weak crimped hairs; sessile spike-lets lanceolate, about 5" long, acuminate, the first scale sulcate on the back, the intercarinal space 2-nerved, the fourth scale with an imperfect awn less than 1/2 its length; pedicellate spikelets stami-nate, a little smaller than the sessile ones, the first scale 9-nerved, not sulcate, the pedicels sparsely pilose with long weak crimped hairs.

In sand, Nebraska and Montana. Summer and fall.