Echinochloa colona
Echinochloa oryzicola
awnless barnyard grass, jungle rice, jungle ricegrass, or jungle-rice, small barnyard grass, watergrass
late barnyard grass, rice barnyardgrass
10-70 cm;
lower nodes glabrous or hispid, hairs appressed;
upper nodes glabrous.
40-150 cm, erect or nearly so, densely tufted;
lower nodes usually antrorsely scabrous or villous;
upper nodes glabrous.
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.
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.
8-20 cm, erect to slightly drooping, rachis nodes hispid,with papillose-based hairs to 5.6 mm, internodes usually scabrous, sometimes also with a few papillose-based hairs;
primary branches to 4 cm.
2-3 mm, disarticulating at maturity, pubescent to hispid, hairs usually not papillose-based, tips acute to cuspidate.
4-6 mm, ovoid to ellipsoid, disarticulating at maturity.
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.
usually at least 1/2 as long as the spikelets;
upper glumes equaling or exceeding the upper florets;
lower florets sterile;
lower lemmas often thickened and somewhat coriaceous, unawned or awned, awns to 1.5 mm;
lower paleas well-developed;
upper lemmas broadly ovate to elliptical, coriaceous portion rounded distally, passing abruptly into an early-withering, acuminate, membranus tip that is further demarcated from the coriaceous portion by minute hairs (use 25x magnification);
anthers 0.9-1.2 mm.
1.2-1.6 mm, whitish;
embryos 63-83% as long as the caryopses.
1.7-2.6 mm, brownish;
embryos 89-98% as long as the caryopses.
sheaths densely pubescent;
upper sheaths glabrous or pubescent at the throat, and sometimes on the collar;
ligules absent;
blades stiff, ascending, lower blades pubescent, upper blades usually glabrous.
= 54.
= 36.
Echinochloa colona
Echinochloa oryzicola
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".
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Like Echinochloa oryzoides, E. oryzicola is an introduced weed of rice fields, where it grows in the flooded portion, with the rice. The two are quite distinct, with E. oryzicola flowering after Oryza and having a longer embryo and an erect panicle. It is also more likely to have evidently pubescent cauline nodes, leaf sheaths, and collars than E. oryzoides and is never conspicuously awned.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
- Local floras:
CA, 
OR, 
WA - Local Web sites: CalFlora, CalPhotos,
Flora NW, 
Go Botany, 
IL Wildflowers, 
KS Wildflowers, 
LA Plants, 
MD Biodiversity, 
MO Plants, 
PNW Herbaria 
WildflowerSearch
iNaturalist (observations)
USDA Plants Database- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
