Letterman's Needlegrass

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, 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 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 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, Inflorescen ce a dense slender spike-like panicle or raceme, branches contracted, Inflorescence solitary, with 1 spike, fascicle, glomerule, head, or cluster per stem or culm, Flowers bisexual, Spikelets pedicellate, Spikelets dorsally compressed or terete, 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 equal to or longer than adjacent lemma, Glumes 3 nerved, Lemma 5-7 nerved, Lemma body or surface hairy, Lemma apex acute or acuminate, Lemma distinctly awned, more than 2-3 mm, Lemma with 1 awn, Lemma awn 1-2 cm long, Lemma awned from tip, Lemma awn twisted, spirally coiled at base, like a corkscrew, Lemma awn twice geniculate, bent twice, Lemma m argins inrolled, tightly covering palea and caryopsis, Lemma straight, Callus or base of lemma evidently hairy, Callus hairs shorter than lemma, Lemma surface pilose, setose or bristly, Palea present, well developed, Palea membranous, hyaline, Palea shorter than lemma, Stamens 3, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis, Caryopsis ellipsoid, longitudinally grooved, hilum long-linear.

Achnatherum lettermanii is a species of grass known by the common name Letterman's needlegrass. The updated and accepted name is Stipa lettermanii. It is native to the western United States from California to Montana to New Mexico, where it is a resident of several types of habitat.

Achnatherum lettermanii is a tufting perennial bunchgrass which forms large clumps of erect stems up to about 80 centimeters tall. The leaves are short and slightly curly. The inflorescence is up to about 19 centimeters long and has open branches with few spikelets. Each spikelet is less than a centimeter long but has an awn which can be up to about 2.5 centimeters in length. The awn has two kinks.