Muhlenbergia sobolifera (Muhl. ex Willd.) Trin.

Muhlenbergia sobolifera (Muhl.) Trin. Gram. Unifl. 189 1824.
Agroslis sobolifera Muhl.; Willd. Enum. 95. 1809.
Achnatherum soboliferum Beauv. Agrost. 20, 146. 1812. (Based on Agroslis sobolifera Muhl.)
Trichochloa sobolifera Trin. Fund. Agrost. 117. 1820. (Based on Agroslis sobolifera Muhl.)
Cinna sobolifera Link. Enum. 1:71. 1821. (Based on Agrosli-i sobolifera Muhl.)
Podosaemum soboliferum Link, Hort. Berol. 1: 83. 1827. (Based on Agroslis sobolifera Muhl.)
Perennial, with numerous creeping scaly rhizomes 2-3 mm. thick; culms erect, slender, solitary or few in a tuft, glabrous or scaberulous below the nodes, 60-100 cm. tall, sparingly branching, the branches erect; sheaths glabrous; ligule truncate, ciliolate, scarcely 0.5 mm. long; blades flat, rather stiffly spreading, scabrous, somewhat narrowed at base, those of the main culm 5-15 cm. long, 3-8 mm. wide, occasionally larger at t'me of flowering, aggregate above the middle of the culm; panicles slender, somewhat nodding, mostly 5-15 cm. long, the distant branches appressed, floriferous from base, overlapping or the lower more distant, the axis glabrous or nearly so, the branches and short pedicels scaberulous; spikelets mostly 2-2.5 mm. long, the glumes about two thirds as long, abruptly acuminate or awn-tipped; lemma elliptic, bluntish, pubescent on the lower part, usually apiculate; palea as long as the lemma.
Type locality: Pennsylvania.
Distribution: Dry rocky woods and cliffs. New Hampshire to Iowa, and southward to Virginia, Tennessee, and Texas.