Oryzopsis

Michx.
Treatment appears in FNA Volume 24. Treatment on page 167.

Plants perennial; cespitose, not rhizomatous. Culms 25-65 cm, erect or spreading, basal branching extravaginal; prophylls not visible; nodes glabrous. Leaves mostly basal; cleistogenes not developed; sheaths open, glabrous; auricles absent; ligules membranous, longest at the sides or rounded, ciliate; blades of basal leaves 30-90 cm, remaining green over winter, erect when young, recumbent in the fall, bases twisted, placing the abaxial surfaces uppermost, cauline leaf-blades reduced, flag leaf-blades 2-12 mm, conspicuously narrower than the top of the sheath. Inflorescences panicles, contracted. Spikelets 5-7.5 mm, with 1 floret; rachillas not prolonged beyond the base of the floret; disarticulation above the glumes, beneath the floret. Glumes subequal, 6-10-veined, apices mucronate; florets terete to laterally compressed; calluses usually less than 1/5 the length of the florets, blunt, distal portions pilose; lemmas coriaceous, pubescent at least basally, 3-5 (9) -veined, margins strongly overlapping at maturity, awned, lemma-awn junction conspicuous, lobed, lobes 0.1-0.2 mm; awns more or less straight, deciduous; paleas similar to the lemmas in length, texture, and pubescence, concealed by the lemmas, 2-veined, flat between the veins; lodicules 2, free, membranous, 2-veined; anthers 3; styles 1, with 2 branches; ovaries glabrous. Caryopses falling with the lemma and palea. x = 11, 12.

Distribution

Wash., Wis., W.Va., Colo., Wyo., N.H., N.J., N.Mex., N.Y., Pa., R.I., Va., Conn., Mass., Maine, Vt., Ill., Ind., Iowa, Idaho, Md., Ohio, Utah, Minn., Mich., N.Dak., S.Dak., Mont., Alta., B.C., Man., N.B., Nfld. and Labr. (Labr.), N.S., N.W.T., Ont., P.E.I., Que., Sask., Yukon

Discussion

Oryzopsis is treated here as a monospecific genus that is restricted to North America. Hitchcock (1951) and Johnson (1945) treated it as including both Eurasian and North American taxa; Freitag (1975) and Tutin (1980) placed the Eurasian species in a separate genus, Piptatherum. Kam and Maze (1974) demonstrated that O. asperifolia differs from both North American and Eurasian species previously included in Oryzopsis in the development of its floret and callus, and in having 2-veined lodicules. Phylogenetic studies based on ITS sequence data have not yielded clear support for any particular treatment of Oryzopsis; they are consistent with the treatment presented here. The North American species previously included in Oryzopsis have been transferred to Achnatherum and Piptatherum.

"decumbent" is not a number."prolonged" is not a number."longest" is not a number.

... more about "Oryzopsis"
membranous +  and scarious +
awned +, bifid +, bilobed +  and entire +
Mary E. Barkworth +
Michx. +
twisted +  and not branched +
1 (?) +  and 3 (?) +
straight +
subterminal +  and eccentric +
0.3 cm3 mm <br />0.003 m <br /> (30 cm300 mm <br />0.3 m <br />) +
keeled +  and rounded +
uppermost +
swelling +
not evident +
cross +, linear +  and narrowly lanceolate +
spikelike +
well-developed +
blunt +  and sharply pointed +
perennial +  and annual +
spreading +  and erect +
extravaginal +  and basal +
25 cm250 mm <br />0.25 m <br /> (65 cm650 mm <br />0.65 m <br />) +
not woody +
Wash. +, Wis. +, W.Va. +, Colo. +, Wyo. +, N.H. +, N.J. +, N.Mex. +, N.Y. +, Pa. +, R.I. +, Va. +, Conn. +, Mass. +, Maine +, Vt. +, Ill. +, Ind. +, Iowa +, Idaho +, Md. +, Ohio +, Utah +, Minn. +, Mich. +, N.Dak. +, S.Dak. +, Mont. +, Alta. +, B.C. +, Man. +, N.B. +, Nfld. and Labr. (Labr.) +, N.S. +, N.W.T. +, Ont. +, P.E.I. +, Que. +, Sask. +  and Yukon +
0 +  and 1/3 +
liquid +, soft +  and hard +
capillary +
pistillate +  and staminate +
sometimes longer +
terete +  and laterally compressed +
1-10-veined +
subtending +
narrowly lanceolate +  and ovate +
subequal +
membranous +
uncinate +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
solid +  and hollow +
basally concentrated +  and evenly distributed +
30 cm300 mm <br />0.3 m <br /> (90 cm900 mm <br />0.9 m <br />) +
3-5(9)-veined +
ovate +, rectangular +  and lanceolate +
coriaceous +
membranous +
inconspicuous +
lanceolate +
concealed +  and prominent +
2 +  and 1 +
well-developed +
reduced +
pubescence +
dry +  and fleshy +
not prolonged +
dore1980b +, freitag1975b +, hitchcock1951a +, jacobs2006a +, johnson1945a +, kam1974a +  and tutin1980a +
1 +  and 60 +
unisexual +  and bisexual +
laterally compressed +  and terete +
0.5 cm5 mm <br />0.005 m <br /> (0.75 cm7.5 mm <br />0.0075 m <br />) +
1 (?) +  and 3 (?) +
simple +  and compound +
2 (?) +  and 3 (?) +
Gramineae +
Oryzopsis +
Poaceae tribe Stipeae +
membranous +
inconspicuous +
plant +  and cespitose +
aquatic +  and terrestrial +