Digitaria ischaemum

(Schreb.) Muhl.
Common names: Smooth crabgrass Digitaire astringente
Introduced
Synonyms: Syntherisma linearis Syntherisma ischaemum
Treatment appears in FNA Volume 25. Treatment on page 372.

Plants annual or of indefinite duration. Culms 20-55(70) cm, decumbent, branching and rooting at the lower nodes; nodes 3-4. Sheaths glabrous or sparsely pubescent; ligules 0.6-2.5 mm; blades 1.5-9 cm long, 3-5 mm wide, glabrous, with a few papillose-based hairs basally. Panicles terminal and axillary; terminal panicles with 2-7 spikelike primary branches, subdigitate or on 0.5-2 cm rachises; primary branches 6-15.5 cm, axes wing-margined, wings at least 1/2 as wide as the midribs, bearing spikelets in groups of 3, lower portions of the longer pedicels adnate to the axes; secondary branches rarely present; axillary inflorescences always present in some of the lower sheaths, entirely or partially concealed. Spikelets 1.7-2.3 mm, homomorphic, narrowly elliptic. Lower glumes absent or a veinless, membranous rim; upper glumes 1.3-2.3 mm, from 3/4 as long as to equaling the upper lemmas, appressed-pubescent; lower lemmas 1.7-2.3 mm, 7-veined, veins unequally spaced, smooth, pubescent; upper lemmas dark brown at maturity; anthers 0.4-0.6 mm. 2n = 36.

Distribution

Idaho, Mont., Wash., Conn., N.J., N.Y., Va., Del., D.C., Wis., W.Va., Md., Alta., B.C., Man., N.B., N.S., Ont., P.E.I., Que., Sask., Fla., Wyo., N.H., N.Mex., Tex., La., Tenn., N.C., S.C., Pa., Nev., Mass., Maine, R.I., Vt., Puerto Rico, Colo., Virgin Islands, Calif., Ala., Kans., N.Dak., Nebr., Okla., S.Dak., Ark., Ill., Ga., Ind., Iowa, Ariz., Ohio, Utah, Mo., Minn., Mich., Miss., Ky., Oreg.

Discussion

Digitaria ischaemum is a Eurasian weed that is now common in lawns, gardens, fields, and waste ground in warm-temperate regions throughout the world, including much of the Flora region. Larger plants with 5-7 inflorescence branches 8-15 cm long have been called var. mississippiensis (Gatt.) Fernald, but they intergrade with more typical plants, and so do not merit taxonomic recognition.

Selected References

None.

Lower Taxa

None.
... more about "Digitaria ischaemum"
J.K. Wipff +
(Schreb.) Muhl. +
Smooth crabgrass +  and Digitaire astringente +
Idaho +, Mont. +, Wash. +, Conn. +, N.J. +, N.Y. +, Va. +, Del. +, D.C. +, Wis. +, W.Va. +, Md. +, Alta. +, B.C. +, Man. +, N.B. +, N.S. +, Ont. +, P.E.I. +, Que. +, Sask. +, Fla. +, Wyo. +, N.H. +, N.Mex. +, Tex. +, La. +, Tenn. +, N.C. +, S.C. +, Pa. +, Nev. +, Mass. +, Maine +, R.I. +, Vt. +, Puerto Rico +, Colo. +, Virgin Islands +, Calif. +, Ala. +, Kans. +, N.Dak. +, Nebr. +, Okla. +, S.Dak. +, Ark. +, Ill. +, Ga. +, Ind. +, Iowa +, Ariz. +, Ohio +, Utah +, Mo. +, Minn. +, Mich. +, Miss. +, Ky. +  and Oreg. +
Introduced +
Syntherisma linearis +  and Syntherisma ischaemum +
Digitaria ischaemum +
Digitaria +
species +