Helictotrichon mortonianum (Scribn.) Henrard

Avena mortoniana Scribn. Bot. Gaz. 21: 133. 1896
Perennial; culms densely tufted, with numerous leafy shoots, 10-20 cm. tall; sheaths pale, papery, retrorsely scabrous to puberulent; ligule minute, pubescent; blades erect, firm, involute, often nearly equaling the panicle, minutely scaberulous; panicle short-exserted, purplish, narrow, 2-5 cm. long, the short branches erect, bearing a single erect, mostly 2-flowered spikelet 1-1.2 cm. long; glumes subequal, exceeding the florets, the first 1-nerved, the second 3-nerved; lemmas firm, 7-8 mm. long, the callus and rachilla white-bearded, the apex hyaline, 4-toothed, the awn twisted, flexuous, 1-1.5 cm. long.
Typb locality: Silver Plume, Colorado (Shear 697).
Distribution: Alpine meadows, Colorado, Utah, and New Mexico.

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 polygonal, Stem internodes hollow, Stems with inflorescence less than 1 m tall, Stems, culms, o r 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 and blade differentiated, Leaf blades linear, Leaf blades very narrow or filiform, less than 2 mm wide, Leaf blade margins folded, involute, or conduplicate, Leaf blades more or less hairy, Ligule present, Ligule an unfringed eciliate membrane, Inflorescence terminal, Inflorescence a contracted panicle, narrowly paniculate, branches appressed or ascending, Inflorescence a dense slender spike-like panicle or raceme, branches contracted, Inflorescence single raceme, fascicle or spike, Inflorescence with 2-10 branches, Flowers bisexual, Spikelets pedicellate, Spikelets laterally compressed, Spikelet less than 3 mm wide, Spikelets with 2 florets, 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 hairy, 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 keeled or winged, Glumes 3 nerved, Glumes 4-7 nerved, Lemma similar in texture to glumes, Lemma 3 nerved, Lemma glabrous, Lemma apex dentate, 3-5 fid, Lemma distinctly awned, more than 2-3 mm, Lemma with 1 awn, Lemma awn 1-2 cm long, Lemma awn subapical or dorsal, Lemma awn twisted, spirally coiled at base, like a corkscrew, Lemma awn once geniculate, bent once, Lemma margins thin, lying flat, Lemma straight, Callus or base of lemma evidently hairy, Callus hairs shorter than lemma, Palea present, well developed, Palea membranous, hyaline, Palea shorter than lemma, Palea 2 nerved or 2 keeled, Palea keels winged, scabrous, or ciliate, Stamens 3, Styles 2-fid , deeply 2-branched, Stigmas 2, Fruit - caryopsis, Caryopsis ellipsoid, longitudinally grooved, hilum long-linear, Caryopsis hairy at apex.

Helictotrichon mortonianum là một loài thực vật có hoa trong họ Hòa thảo. Loài này được (Scribn.) Henrard mô tả khoa học đầu tiên năm 1940.