Echinochloa muricata |
Echinochloa polystachya |
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American barnyard-grass, awn barnyard grass, rough barnyard grass |
creeping river grass |
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Habit | Plants annual. | Plants perennial; not rhizomatous. | ||||
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. |
1-2 m tall, to 1 cm thick, erect or decumbent and rooting at the lower nodes, upper portion sometimes floating distally; nodes glabrous or antrorsely villous. |
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Sheaths | glabrous; ligules absent; blades 1-27 cm long, 0.8-30 mm wide. |
mostly glabrous, minutely puberulent, or hispid, hairs papillose-based, throat hispid; ligules present on the lower leaves, 1-5 mm, of stiff hairs; blades 15-70 cm long, 5-13 mm wide, glabrous. |
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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. |
13-45 cm, erect, rachis nodes hispid, hairs 3-6.5 mm, papillose-based, internodes scabrous; primary branches 4-10 cm, subverticillate, ascending, nodes hispid, hairs 2.5-4 mm, papillose-based, internodes scabrous; secondary branches short, spikelets subsessile, in clusters. |
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Spikelets | 2.5-5 mm, disarticulating at maturity, usually purple or streaked with purple, usually hispid, hairs papillose-based. |
4-7 mm, hispid, hairs appressed, disarticulating at maturity. |
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Lower glumes | at least 1/2 as long as the spikelets; lower florets staminate; lower lemmas apiculate or awned, awns to 18 mm; lower paleas subequal to the lower lemmas, often purple; anthers of lower florets 1.5-3.6 mm, orange; upper lemmas 2.5-5 mm, elliptic or narrowly ovate, apices obtuse, with a membranous, soon-withering tip; anthers of upper florets shorter than those of the lower florets. |
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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. |
to 3 mm. |
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2n | = 36. |
= 54. |
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Echinochloa muricata |
Echinochloa polystachya |
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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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FL; LA; TX; PR |
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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 polystachya grows in coastal marshes, often in standing water, from Texas, Louisiana, and Florida south through Mexico and the Caribbean islands to Argentina. Two varieties exist. Echinochloa polystachya var. polystachya has glabrous culms and leaf sheaths; Echinochloa polystachya var. spectabilis (Nees ex Trin.) Mart. Crov. has swollen, pubescent cauline nodes and pubescent leaf sheaths. (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. 394. | ||||
Parent taxa | Poaceae > subfam. Panicoideae > tribe Paniceae > Echinochloa | Poaceae > subfam. Panicoideae > tribe Paniceae > Echinochloa | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Name authority | (P. Beauv.) Fernald | (Kunth) Hitchc. | ||||
Web links |
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