Echinochloa colona
Echinochloa walteri
awnless barnyard grass, jungle rice, jungle ricegrass, or jungle-rice, small barnyard grass, watergrass
coast barnyard grass, coast cockspur, coast cockspur grass, echinochloa de Walter, Walter's barnyard grass
10-70 cm;
lower nodes glabrous or hispid, hairs appressed;
upper nodes glabrous.
(30) 50-200+ cm tall, to 2.5 cm thick;
nodes pilose or villous, upper nodes usually with sparser and shorter pubescence, occasionally 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.
8.5-35 cm, erect to slightly drooping, nodes hispid, hairs 3.5-5 mm, papillose-based, sometimes sparsely so, internodes usually glabrous, sometimes hispid, hairs papillose-based;
primary branches 1-10 cm, loosely erect, not concealed by the spikelets, nodes usually hispid, hairs papillose-based, sometimes glabrous, internodes scabrous, sometimes also sparsely hispid, hairs papillose-based;
secondary branches present on the longer primary branches.
2-3 mm, disarticulating at maturity, pubescent to hispid, hairs usually not papillose-based, tips acute to cuspidate.
3-5 mm, disarticulating at maturity, scabrous to variously muricate and hairy, hairs usually not papillose-based, margins sometimes with a few papillose-based hairs.
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 more than 1/2 as long as the spikelets, abruptly narrowing to a fine, 0.5 mm point;
lower florets sterile;
lower lemmas usually awned, awns 8-25(60) mm;
lower paleas subequal to the lower lemmas;
upper lemmas 3-5 mm long, about 1.5 mm wide, not or scarcely exceeding the upper glumes, narrowly ovate to elliptical, coriaceous portion subacute, tips acuminate, membranous, without a line of hairs at the base of the tip;
anthers 0.6-1(1.2) mm.
1.2-1.6 mm, whitish;
embryos 63-83% as long as the caryopses.
1.2-1.8 mm, brownish;
embryos 52-77% as long as the caryopses.
sheaths usually hispid, hairs papillose-based, sometimes just papillose;
upper sheaths hispid or glabrous;
ligules absent;
blades to 55 cm long, 10-35(60) mm wide, scabrous.
= 54.
= 36.
Echinochloa colona
Echinochloa walteri
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.)
Echinochloa walteri grows in wet places, often in shallow water and brackish marshes. It is a native species that extends through Mexico to Guatamala. It is found in both disturbed and undisturbed sites although not in rice fields. Occasional specimens of E. walteri with glabrous lower sheaths and short awns can be distinguished from E. crus-pavonis by their less dense panicles.
(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
MI Flora
MN Wildflowers
