Echinochloa muricata |
Echinochloa colona |
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American barnyard-grass, awn barnyard grass, rough barnyard grass |
awnless barnyard grass, jungle rice, jungle ricegrass, or jungle-rice, small barnyard grass, watergrass |
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Habit | Plants annual. | Plants annual; erect or decumbent, cespitose or spreading, rooting from the lower cauline nodes. | ||||
Culms | 80-160 cm, erect or spreading, sometimes rooting at the lowest nodes, often developing short axillary flowering shoots at most upper nodes when mature; lower nodes glabrous or puberulent; upper nodes glabrous. |
10-70 cm; lower nodes glabrous or hispid, hairs appressed; upper nodes glabrous. |
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Sheaths | glabrous; ligules absent; blades 1-27 cm long, 0.8-30 mm wide. |
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. |
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Panicles | of primary culms 7-35 cm, rachises and branches glabrous or hispid, hairs to 3 mm, papillose-based; primary branches 2-8 cm, usually spreading and rather distant, often with secondary branches. |
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. |
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Spikelets | 2.5-5 mm, disarticulating at maturity, usually purple or streaked with purple, usually hispid, hairs papillose-based. |
2-3 mm, disarticulating at maturity, pubescent to hispid, hairs usually not papillose-based, tips acute to cuspidate. |
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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. |
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Upper glumes | about as long as the spikelets; lower florets sterile; lower lemmas unawned or awned, awns to 16 mm; lower paleas well-developed; upper lemmas broadly obovoid or orbicular, narrowing to an acute or acuminate coriaceous portion that extends into the membranous tip, boundary between the coriaceous and membranous portions not marked by minute hairs; anthers 0.4-1.1 mm. |
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Caryopses | 1.2-2.5 mm, broadly obovoid or spheroid, yellowish; embryos 1.4-2 mm, 80-91% as long as the caryopses. |
1.2-1.6 mm, whitish; embryos 63-83% as long as the caryopses. |
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2n | = 36. |
= 54. |
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Echinochloa muricata |
Echinochloa colona |
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Distribution |
AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; MB; NB; NS; ON; QC; SK; Virgin Islands
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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 muricata is native to North America, growing from southern Canada to northern Mexico in moist, often disturbed sites (but not rice fields). It resembles E. crus-galli in gross morphology and ecology, but differs consistently by the characters used in the key. The two varieties tend to be distinct, but there is some overlap in both morphology and geography. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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.) |
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Key |
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Source | FNA vol. 25, p. 396. | FNA vol. 25, p. 398. | ||||
Parent taxa | Poaceae > subfam. Panicoideae > tribe Paniceae > Echinochloa | Poaceae > subfam. Panicoideae > tribe Paniceae > Echinochloa | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | E. colonum | |||||
Name authority | (P. Beauv.) Fernald | (L.) Link | ||||
Web links |
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