Echinochloa colona |
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awnless barnyard grass, jungle rice, jungle ricegrass, or jungle-rice, small barnyard grass, watergrass |
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Habit | 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. |
Caryopses | 1.2-1.6 mm, whitish; embryos 63-83% as long as the caryopses. |
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. |
2n | = 54. |
Echinochloa colona |
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Distribution |
AL; AR; AZ; CA; FL; GA; IL; KS; KY; LA; MA; MD; MO; MS; MT; NC; NJ; NM; OK; OR; PA; SC; TN; TX; VA; VT; WA; HI; PR; Virgin Islands
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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". (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 25, p. 398. |
Parent taxa | Poaceae > subfam. Panicoideae > tribe Paniceae > Echinochloa |
Sibling taxa | |
Synonyms | E. colonum |
Name authority | (L.) Link |
Web links |
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