Torreyochloa

Plants perennial; rhizomatous. Culms 18-145 cm, usually erect, sometimes decumbent and rooting at the lower nodes; internodes hollow. Sheaths open to the base; auricles absent; ligules membranous; blades flat. Inflorescences terminal panicles; branches scabrous, usually densely scabrid distally; pedicels less than 0.5 mm thick. Spikelets pedicellate, laterally compressed to terete, with 2-8 florets; disarticulation above the glumes and beneath the florets. Glumes unequal, shorter than the lowest lemma, rounded to weakly keeled, membranous, veins obscure to prominent, unawned; lower glumes 1(3)-veined; upper glumes (1)3(5)-veined; calluses blunt, glabrous; lemmas membranous, rounded to weakly keeled, sometimes pubescent, particularly proximally, prominently (5)7-9-veined, veins more or less parallel, veins and interveins usually scabridulous, particularly distally, lateral veins usually reduced or absent, apices scabridulous and entire to serrate-erose, unawned; paleas subequal to the lemmas, 2-veined; lodicules 2, free, glabrous, entire or toothed; anthers usually 3; ovaries usually hairy, sometimes glabrous. Caryopses shorter than the lemmas, concealed at maturity, oblong, flattened dorsally, falling free; hila oblong, about 1/3 the length of the caryopses. x = 7.

Distribution

Conn., N.J., N.Y., Wash., Del., Wis., W.Va., Mass., Maine, N.H., R.I., Vt., Wyo., N.Mex., N.C., Alta., B.C., Man., N.B., Nfld. And Labr., N.S., Ont., P.E.I., Que., Sask., Yukon, Tenn., Pa., Calif., Nev., Va., Colo., Alaska, Ill., Ga., Ind., Ariz., Idaho, Md., Ohio, Utah, Mo., Minn., Mich., Mont., S.C., Ky., Oreg., S.Dak.

Discussion

Torreyochloa grows in cold, wet, non-saline environments. It includes the two North American species treated below, plus two additional taxa in northeastern Asia (Koyama & Kawano 1964). Although similar to Glyceria and Puccinellia, Torreyochloa is not closely related to either (Church 1952; Soreng et al. 1990). It is distinguished from Glyceria by its open leaf sheaths, and from Puccinellia by the 7-9 (occasionally 5) prominent, rather than faint, lemma veins.

Selected References

Church, G.L. 1952. The genus Torreyochloa. Rhodora 54:197-200

Koyama, T. and S. Kawano. 1964. Critical taxa of grasses with North American and eastern Asiatic distribution. Canad. J. Bot. 42:859-884

Soreng, R.J., J.I. Davis, and J.J. Doyle. 1990. A phylogenetic analysis of chloroplast DNA restriction site variation in the Poaceae subfam. Pooideae. PL Syst. Evol. 172:83-97.

Lower Taxa

Torreyochloa erecta, Torreyochloa pallida

Key

1	Mature inflorescences linear to narrowly elliptic, 0.3-1 cm wide, 5.5-19 times as long as wide; widest cauline blades 3.4-7.2 mm wide	Torreyochloa erecta
1	Mature inflorescences conic, ovoid, or obovoid, 1-16 cm wide, 1-7.5 times as long as wide; widest cauline blades 1.5-18 mm wide	Torreyochloa pallida