Rock Muhly

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.

Perennials, Terrestrial, not aquatic, Rhizomes present, Rhizome elongate, creeping, stems distant, Stems trai ling, spreading or prostrate, Stems nodes swollen or brittle, Stems erect or ascending, Stems geniculate, decumbent, or lax, sometimes rooting at nodes, Stems solitary, Stems caespitose, tufted, or clustered, Stems terete, round in cross section, or polygonal, Stem internodes hollow, Stems with inflorescence less than 1 m tall, Stems, culms, or scapes exceeding basal leaves, Leaves mostly basal, below middle of stem, Leaves mostly cauline, Leaves conspicuously 2-ranked, distichous, Leaves sheathing at base, Leaf sheath mostly open, or loose, Leaf sheath smooth, glabrous, Leaf sheath hairy, hispid or prickly, Leaf sheath and blade differentiated, Leaf blades linear, Leaf blades 2-10 mm wide, Leaf blades mostly flat, Leaf blades mostly glabrous, Leaf blades scabrous, roughened, or wrinkled, Ligule present, Ligule an unfringed eciliate membrane, Inflorescence terminal, Inflorescence a contracted panicle, narrowly paniculate, branches appressed or ascending, Inflorescence soli tary, with 1 spike, fascicle, glomerule, head, or cluster per stem or culm, Inflorescence branches more than 10 to numerous, Flowers bisexual, Spikelets pedicellate, Spikelets laterally compressed, Spikelet less than 3 mm wide, Spikelets with 1 fertile floret, Spikelets solitary at rachis nodes, Spikelets all alike and fertille, Spikelets bisexual, Spikelets disarticulating above the glumes, glumes persistent, Spikelets disarticulating beneath or between the florets, Rachilla or pedicel glabrous, Glumes present, empty bracts, Glumes 2 clearly present, Glumes equal or subequal, Glumes shorter than adjacent lemma, Glumes 1 nerved, Lemmas thin, chartaceous, hyaline, cartilaginous, or membranous, Lemma similar in texture to glumes, Lemma 3 nerved, Lemma glabrous, Lemma apex truncate, rounded, or obtuse, Lemma awnless, Lemma mucronate, very shortly beaked or awned, less than 1-2 mm, Lemma margins thin, lying flat, Lemma straight, Callus or base of lemma evidently hairy, Callus ha irs shorter than lemma, Palea present, well developed, Palea membranous, hyaline, Palea about equal to lemma, Palea 2 nerved or 2 keeled, Stamens 3, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis, Caryopsis ellipsoid, longitudinally grooved, hilum long-linear.