Comprehensive Description
provided by North American Flora
Pleuraphis jamesii Torr. Ann. I,yc. N. Y. 1 : 148. 1824
Hilaria Jamesii Benth. Jour. I^inn. See. 19 : 62. 1881,
Stems 1.5-5 dm. tall, erect, simple, usually hispidulous or puberulent below the inflorescence and below the nodes which are generally barbed; leaf-sheaths smooth or rough, glabrous; blades confined mainly to the lower portion of the stem, up to 2 dm. long, 2-3 mm. wide, spreading or erect, the margins involute, rough on the lower surface, the upper surface densely puberulent; inflorescence 3-7 cm. long, the axis commonly puberulent; spikelet-clusters 7-9 mm. long, about twice as long as the basal hairs; lateral spikelets with the empty scales linear-oblong, 3or 4-nerved, the nerves parallel, strongly hispidulous all over on the outside,
F
ciliate on the margins, 2-lobed, the flrst scale shorter than the second, strongly inequilateral,
the one lobe very narrow, as long as the other lobe or but little shorter, the midnerve
excurrent as a hispid awn between the lobes, much longer than the scale, the remaining nerves
vanishing below the apex, the second scale entire or minutely bifid at the apex, the nerves
vanishing at or below the apex or the midnerve sometimes excurrent as a short hispid point,
the flowering scales usually 2, 3or rarely 5-nerved; central spikelet with the empty scales
long-ciliate, the apex divided into 4—8 long-awned lobes, the midnerve excurrent usually at
or below the middle as a hispid awn longer than the scale, the flowering scale 3-nerved, or
rarely with an additional nerve on one side, the midnerve excurrent between the lobes as a
short hispid awn.
Type locality : On the high plains of the trap formation at the sources of the Canadian River. Distribution : Wyoming to Nevada, and south to western Texas and southern California.
- bibliographic citation
- George Valentine Nash. 1912. (POALES); POACEAE (pars). North American flora. vol 17(2). New York Botanical Garden, New York, NY
Physical Description
provided by USDA PLANTS text
Perennials, Terrestrial, not aquatic, Rhizomes present, Rhizome short and compact, stems close, Stolons or runners present, Stems nodes swollen or brittle, Stems erect or ascending, Stems geniculate, decumbent, or lax, sometimes rooting at nodes, Stems caespitose, tufted, or clustered, Stems terete, round in cross section, or polygonal, Stem nodes bearded or hairy, Stem internodes hollow, Stems with inflorescence less than 1 m tall, Stems, culms, or scapes exceeding basal leaves, 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 at summit, throat, or collar, Leaf sheath and blade differentiated, Leaf blades linear, Leaf blades 2-10 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 dense slender spike-like panicle or raceme, branches contracted, Inflorescence solitary, with 1 spike, fascicle, glomerule, head, or cluster per stem or culm, Inflorescence a panicle with narrowly racemose or spicate branches, Inflorescence branches more than 10 to numerous, Inflorescence branches 1-sided, Flowers bisexual, Flowers unisexual, Spikelets sessile or subsessile, Spikelets laterally compressed, Spikelet less than 3 mm wide, Spikelets with 1 fertile floret, Spikelets with 3-7 florets, Spikelets 3 per node, Spikelets with 1 terminal fertile floret and 2 lateral staminate or sterile florets, Spikelets bisexual, Spikelets unisexual, Spikelets falling with parts of disarticulating rachis or pedicel, Inflorescence branches deciduous, falling intact, Spikelets secund, in rows on one side of rachis, Glumes present, empty bracts, Glumes 2 clearly present, Glumes di stinctly unequal, Glumes shorter than adjacent lemma, Glumes equal to or longer than adjacent lemma, Glumes awned, awn 1-5 mm or longer, Glumes keeled or winged, Glumes 4-7 nerved, Glumes 2-5 toothed, Glume margins or apex erose-ciliate, Glumes prominently lobed, Lemmas thin, chartaceous, hyaline, cartilaginous, or membranous, Lemma 3 nerved, Lemma glabrous, Lemma apex dentate, 2-fid, Lemma distinctly awned, more than 2-3 mm, Lemma with 1 awn, Lemma awn less than 1 cm long, Lemma awn from sinus of bifid apex, Lemma awns straight or curved to base, Lemma margins thin, lying flat, Lemma straight, Palea present, well developed, Palea membranous, hyaline, Palea about equal to lemma, Stamens 2, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis.