Echinochloa colona

(L.) Link
Common names: Awnless barnyard grass
Introduced
Synonyms: Echinochloa colonum
Treatment appears in FNA Volume 25. Treatment on page 398.

Plants annual; erect or decumbent, cespitose or spreading, rooting from the lower cauline nodes. Culms 10-70 cm; lower nodes glabrous or hispid, hairs appressed; upper nodes glabrous. Sheaths glabrous; ligules absent, ligule region frequently brown-purple; blades 8-22 cm long, 3-6 (10) mm wide, mostly glabrous, sometimes hispid, hairs papillose-based on or near the margins. Panicles 2-12 cm, erect, rachises glabrous or sparsely hispid; primary branches 5-10, 0.7-2 (4) cm, erect to ascending, spikelike, somewhat distant, without secondary branches, axes glabrous or sparsely hispid, hairs 1.5-2.5 mm, papillose-based. Spikelets 2-3 mm, disarticulating at maturity, pubescent to hispid, hairs usually not papillose-based, tips acute to cuspidate. Lower glumes about 1/2 as long as the spikelets; upper glumes about as long as the spikelets; lower florets usually sterile, occasionally staminate; lower lemmas unawned, similar to the upper glumes; lower paleas subequal to the lemmas; upper lemmas 2.6-2.9 mm, not or scarcely exceeding the upper glumes, elliptic, coriaceous portion rounded distally, passing abruptly into a sharply differentiated, membranous, soon-withering tip; anthers 0.7-0.8 mm. Caryopses 1.2-1.6 mm, whitish; embryos 63-83% as long as the caryopses. 2n = 54.

Distribution

Mont., Oreg., Wash., Pacific Islands (Hawaii), Fla., N.J., N.Mex., Tex., La., Tenn., N.C., S.C., Pa., Va., Calif., Puerto Rico, Virgin Islands, Ala., Ark., Vt., Ill., Ga., Mass., Ariz., Md., Okla., Mo., Kans., Miss., Ky.

Discussion

Echinochloa colona is widespread in tropical and subtropical regions. It is adventive and weedy in North America, growing in low-lying, damp to wet, disturbed areas, including rice fields. The unbranched, rather widely-spaced panicle branches make this one of the easier species of Echinochloa to recognize.

Hitchcock (1913) considered that 'colonum' was a non-declining contraction, but dictionaries of Linnaeus' time treated it as a declining adjective. Because Linnaeus was the first to name the species (as "Panicum colonum"), it seems best to follow the practice considered correct in his day; hence "E. colona".

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

... more about "Echinochloa colona"
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.08 cm0.8 mm <br />8.0e-4 m <br />) +
elongate +
membranous +  and firm +
anatomy +  and kranz +
P.W. Michael +
(L.) Link +
1 (?) +  and 3 (?) +
0 cm0 mm <br />0 m <br /> (6 cm60 mm <br />0.06 m <br />) +
hispid +  and glabrous +
keeled +  and rounded +
pseudopetiolate +  and branching +
divergent +  and parallel +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
membranous +
disarticulating +  and pseudopetiolate +
non-radiate +  and radiate +
8 cm80 mm <br />0.08 m <br /> (22 cm220 mm <br />0.22 m <br />) +
hispid +  and glabrous +
linear +  and linear-lanceolate +
0.3 cm3 mm <br />0.003 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
subsessile +, compound +  and simple +
spikelike +
0 cm0 mm <br />0 m <br /> (1 cm10 mm <br />0.01 m <br />) +
not developed +
spheroid +, ovoid +  and ellipsoid +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.16 cm1.6 mm <br />0.0016 m <br />) +
sometimes longer +
Awnless barnyard grass +
branched +  and solid +
erect +  and decumbent +
10 cm100 mm <br />0.1 m <br /> (70 cm700 mm <br />0.7 m <br />) +
Mont. +, Oreg. +, Wash. +, Pacific Islands (Hawaii) +, Fla. +, N.J. +, N.Mex. +, Tex. +, La. +, Tenn. +, N.C. +, S.C. +, Pa. +, Va. +, Calif. +, Puerto Rico +, Virgin Islands +, Ala. +, Ark. +, Vt. +, Ill. +, Ga. +, Mass. +, Ariz. +, Md. +, Okla. +, Mo. +, Kans. +, Miss. +  and Ky. +
0.7-0.9 times as long as the caryopses +
capillary +
germination +
pistillate +  and staminate +
sometimes longer +
compressed +  and terete +
shorter or longer +
subtending +
unequal +
membranous +
papillose-based +
pubescent +  and hispid +
acute +  and cuspidate +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
bracteate +  and ebracteate +
solid +  and hollow +
cauline +  and basal +
coriaceous +
membranous +
inconspicuous +
hispid +  and glabrous +
complex +  and simple +
concealed +  and prominent +
2 +  and 1 +
subterranean +
2 cm20 mm <br />0.02 m <br /> (12 cm120 mm <br />0.12 m <br />) +
dry +  and fleshy +
coriaceous +
4 cm40 mm <br />0.04 m <br /> (?) +
0.7 cm7 mm <br />0.007 m <br /> (2 cm20 mm <br />0.02 m <br />) +
hispid +  and glabrous +
elongate +
compressed +
Introduced +
disarticulating +
in triplets +  and paired +
1 +  and 60 +
unisexual +  and bisexual +
planoconvex +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
1 +  and 3 +
fused +  and free +
2 +  and 3 +
dome--shaped +  and triangular +
Echinochloa colonum +
Echinochloa colona +
Echinochloa +
species +
papillose-based +
soon-withering +  and maturity +
pubescent;hispid +
acute +  and cuspidate +
membranous +
differentiated +
membranous +
0.26 cm2.6 mm <br />0.0026 m <br /> (0.29 cm2.9 mm <br />0.0029 m <br />) +
aquatic +  and terrestrial +
dioecious +, monoecious +  and synoecious +