Echinochloa oryzoides

(Ard.) Fritsch
Common names: Early barnyard grass
Introduced
Treatment appears in FNA Volume 25. Treatment on page 402.

Plants annual. Culms 40-120 cm, erect, densely tufted; nodes glabrous. Sheaths glabrous; ligules absent; blades lax or drooping, 7-20 cm long, 4-12 mm wide, mostly glabrous. Panicles 8-17 (25) cm, lax, horizontal to strongly drooping, rachis nodes hispid, hairs to 4 mm, papillose-based, internodes glabrous; primary branches to 5 cm, appressed to the rachises, mostly simple, glabrous or sparsely hispid, hairs to 3.5 mm, papillose-based, particularly at the nodes. Spikelets 3.7-7 mm long, 1.9-2.4 mm wide, disarticulating at maturity, broadly ovate to ovate. Lower glumes usually 1/4 - 2/5 as long as the spikelets, occasionally 1/2 as long or longer; upper glumes subequal to the spikelets; lower florets sterile; lower lemmas similar in size to the spikelet, usually awned, awns to 5 cm; lower paleas well-developed; upper lemmas 3.5-4.5 mm, similar in length and width to the upper glumes, broadly elliptic to ovate, with an acute, greenish tip; anthers to 0.8 mm. Caryopses 1.9-3 mm, light-brown or tan; embryos 70-85% as long as the caryopses. 2n = 54.

Distribution

Calif., Pacific Islands (Hawaii)

Discussion

Echinochloa oryzoides is a common weed of rice fields throughout the world, growing in the flooded portions of the fields. It was included in E. oryzicola by Gould et al. (1972), but it differs in its shorter embryo, lax, strongly drooping panicle, and earlier (June-July) flowering period. This flowering period is also earlier than that of Oryza. In addition, E. oryzoides is usually conspicuously awned, having longer awns than even the awned variants of E. oryzicola, and it is rarely obviously pubescent on the cauline nodes, leaf sheaths, and collars. The earliest known collection of E. oryzoides in the United States was made in 1925 (Barrett and Seaman 1980).

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

... more about "Echinochloa oryzoides"
0 cm0 mm <br />0 m <br /> (0.08 cm0.8 mm <br />8.0e-4 m <br />) +
elongate +
membranous +  and firm +
anatomy +  and kranz +
P.W. Michael +
(Ard.) Fritsch +
1 (?) +  and 3 (?) +
0 cm0 mm <br />0 m <br /> (5 cm50 mm <br />0.05 m <br />) +
keeled +  and rounded +
pseudopetiolate +  and branching +
divergent +  and parallel +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
membranous +
disarticulating +  and pseudopetiolate +
7 cm70 mm <br />0.07 m <br /> (20 cm200 mm <br />0.2 m <br />) +
linear +  and linear-lanceolate +
0.4 cm4 mm <br />0.004 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
subsessile +, compound +  and simple +
spikelike +
0 cm0 mm <br />0 m <br /> (1 cm10 mm <br />0.01 m <br />) +
not developed +
tan +  and light-brown +
spheroid +, ovoid +  and ellipsoid +
0.19 cm1.9 mm <br />0.0019 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
sometimes longer +
Early barnyard grass +
branched +  and solid +
40 cm400 mm <br />0.4 m <br /> (120 cm1,200 mm <br />1.2 m <br />) +
Calif. +  and Pacific Islands (Hawaii) +
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 +
uncinate +
0 cm0 mm <br />0 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
bracteate +  and ebracteate +
solid +  and hollow +
cauline +  and basal +
coriaceous +
membranous +
inconspicuous +
longer +  and long +
1/4 +  and 2/5 +
complex +  and simple +
concealed +  and prominent +
2 +  and 1 +
25 cm250 mm <br />0.25 m <br /> (?) +
subterranean +
horizontal +  and strongly drooping +
8 cm80 mm <br />0.08 m <br /> (17 cm170 mm <br />0.17 m <br />) +
dry +  and fleshy +
hispid +  and glabrous +
0 cm0 mm <br />0 m <br /> (5 cm50 mm <br />0.05 m <br />) +
elongate +
compressed +
Introduced +
disarticulating +
in triplets +  and paired +
0.37 cm3.7 mm <br />0.0037 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
unisexual +  and bisexual +
broadly ovate +  and ovate +
1.9mm +  and 2.4mm +
1 +  and 3 +
fused +  and free +
2 +  and 3 +
dome--shaped +  and triangular +
Gramineae +
Echinochloa oryzoides +
Echinochloa +
species +
membranous +
broadly elliptic +  and ovate +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
aquatic +  and terrestrial +
dioecious +, monoecious +  and synoecious +