Cynosurus

Plants annual or perennial; sometimes rhizomatous. Culms 1.5-90 cm, erect. Cauline leaves 1-3; sheaths open to the base; auricles absent; ligules truncate, entire, erose, or ciliolate; blades flat. Inflorescences terminal panicles, condensed, often spikelike, linear to almost globose, more or less unilateral; branches and pedicels stiff, straight, smooth and glabrous or almost so, sometimes slightly scabridulous, scabrules/hairs to 0.1 mm. Spikelets dimorphic, usually paired, subsessile to shortly pedicellate, laterally compressed, proximal spikelet of each pair sterile, almost completely concealing the fertile spikelet, distal spikelet on each branch sometimes solitary; disarticulation above the glumes, beneath the florets. Sterile spikelets persistent, with 6-18 florets, florets reduced to narrow, linear-lanceolate lemmas, sometimes awned, awns terminal; glumes narrow, linear. Fertile spikelets adaxial to the sterile spikelets, with 1-5 florets; rachillas glabrous, prolonged beyond the base of the distal floret; glumes 2, subequal and shorter than the spikelets, thin, lanceolate, 1-veined, acute, sometimes awned; calluses short, blunt, glabrous; lemmas glabrous or pubescent, 5-veined, acute or bidentate, unawned to conspicuously awned, awns terminal; paleas about as long as the lemmas, bifid; lodicules 2, free, glabrous, ovate, bilobed; anthers 3; ovaries broadly ellipsoid, glabrous; styles separate. Caryopses oblong-ellipsoid, subterete, slightly dorsally compressed, sometimes adherent to the paleas: hila 1/5-1/2 as long as the caryopses, oblong to linear. x = 7.

Distribution

Mont., Oreg., Conn., N.J., N.Y., Wash., Del., Wis., W.Va., N.H., N.Mex., Tex., La., Tenn., N.C., S.C., Pa., B.C., Nfld. And Labr. (Labr.), N.S., Ont., Que., Va., Colo., Calif., Ala., Ark., Vt., Ga., Okla., Idaho, Maine, Md., Mass., Ohio, Mo., Mich., R.I., Miss.

Discussion

Cynosurus is a genus of eight species that grow in open, grassy, often weedy habitats. It is native around the Mediterranean and in western Asia. The affinities of the genus are obscure. Two species are established in the Flora region.

Selected References

Ennos, R.A. 1985. The mating system and genetic structure in a perennial grass, Cynosurus cristatus L. Heredity 55:121-126

Jirasek, V. and J. Chrtek. 1964. Zur frage des taxonomischen Wertes der Gattung Cynosurus L. Novit. Bot. Delect. Seminum Horti Bot. Univ. Carol. Prag. 20:23-27

Lodge, R.W. 1959. Biological flora of the British Isles: Cynosurus cristatus L. J. Ecol. 47:511-518.

Lower Taxa

Cynosurus cristatus, Cynosurus echinatus

Key

1	Plants perennial; panicles linear; fertile lemmas unawned or with awns shorter than 3 mm	Cynosurus cristatus
1	Plants annual; panicles ovoid to almost globose; fertile lemmas with awns 5-25 mm long	Cynosurus echinatus