Idaho Bentgrass

Agrostis idahoensis Nash, Bull. Torrey Club 24: 42. 1897
Agrostis tenuis Vasey, Bull. Torrey Club 10: 21. 1883. (Type from San Bernardino Mountains,
California, Parish Brothers 1085.) Not A. tenuis Sibth. 1794. Agrostis tenuiculmisNash; Rydb.Mem. N. Y. Bot. Gard. 1:32. 1900. (Based on A . tenuis Vasey.) Agrostis tenuiculmis recta Nash; Rydb. Mem. N. Y. Bot. Gard. 1: 32. 1900. (Type from Belt
Pass, Montana, Rydberg 3327.)
Perennial; culms slender, cespitose, erect, glabrous, 10-30 cm. tall; leaves mostly basal, the sheaths glabrous; ligule 1-2 mm. long; blades flat or more or less involute, glabrous beneath, scaberulous on the upper surface, mostly less than 1 mm. wide; panicle loosely spreading, 5-10 cm. long, the branches capillary, flexuous, naked below, scabrous; glumes about 1.5 mm. long, sometimes as much as 2 mm., acute; lemma about 1.3 mm. long, awnless; palea minute.
Type locality: Forest, Idaho (Heller 3431).
Distribution: Mountain meadows, at medium and high altitudes, western Montana to Washington, and southward to New Mexico and the high mountains of southern California; Fairbanks, Alflsks.

Perennials, Terrestrial, not aquatic, Stems nodes swollen or brittle, Stems erect or ascending, Stems caespitose, tufted, or clustered, Stems terete, round in cross section, or polygona l, 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 conspicuously 2-ranked, distichous, Leaves sheathing at base, Leaf sheath mostly open, or loose, Leaf sheath smooth, glabrous, Leaf sheath and blade differentiated, Leaf blades linear, Leaf blades very narrow or filiform, less than 2 mm wide, Leaf blades 2-10 mm wide, Leaf blades mostly flat, Leaf blade margins folded, involute, or conduplicate, Leaf blades mostly glabrous, Ligule present, Ligule an unfringed eciliate membrane, Inflorescence terminal, Inflorescence an open panicle, openly paniculate, branches spreading, Inflorescence solitary, with 1 spike, fascicle, glomerule, head, or cluster per stem or culm, Inflorescence branches more than 10 to numerous, Lower panicle branches whorled, Flowers bisexual, Spikelets laterally compressed, Spikelet less than 3 mm wide, Spikelets with 1 fertile floret, Spike lets 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, Entire inflorescence falling intact, as a tumbleweed, Rachilla or pedicel glabrous, Glumes present, empty bracts, Glumes 2 clearly present, Glumes equal or subequal, Glumes equal to or longer than adjacent lemma, Glume equal to or longer than spikelet, Glumes 1 nerved, Lemmas thin, chartaceous, hyaline, cartilaginous, or membranous, Lemma 5-7 nerved, Lemma glabrous, Lemma apex truncate, rounded, or obtuse, Lemma awnless, Lemma margins thin, lying flat, Lemma straight, Palea present, well developed, Palea membranous, hyaline, Palea shorter than 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.

Agrostis idahoensis is a species of grass known by the common name Idaho bent grass. It is native to western North America from Alaska to California to Colorado, where it grows in several habitat types.