Digitaria filiformis |
Digitaria abyssinica |
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slender crabgrass |
African couchgrass |
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Habit | Plants annual, or short-lived perennials; cespitose, not rhizomatous. | Plants perennial; rhizomatous, mat-forming. | ||||||||||||
Culms | (10)25-150 cm, erect or decumbent, branching, sometimes rooting at the lower nodes; nodes 3-6. |
5-80 cm, decumbent, occasionally rooting at the lower nodes, branching freely at the base, erect portion 20-40 cm; nodes 2-6. |
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Sheaths | keeled, basal sheaths usually with papillose-based hairs, rarely glabrous; ligules 0.3-1.5 mm; blades 2-18 cm long, 1-6 mm wide, flat or involute, glabrous, scabrous, or pilose. |
of midculm leaves glabrous or hirsute, with papillose-based hairs; ligules 0.8-2.1 mm; blades 4-15 cm long, 3-10 mm wide, glabrous or sparsely pubescent with papillose-based hairs. |
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Panicles | with 2-7 spikelike primary branches, these digitate or the rachises to 1 cm; longest primary branches 20-25 cm, axes triquetrous, not winged, with spikelets in unequally pedicellate groups of 3(-5) on the basal ½ (J. |
with 2-25 spikelike primary branches on 1-9 cm rachises; primary branches 2-11 cm, axes not winged or narrowly winged, wings less than 1/2 as wide as the midribs, bearing spikelets in unequally pedicellate pairs; secondary branches rarely present; pedicels not adnate to the branch axes. |
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Spikelets | 1.3-2.8 mm. |
1.5-2.5 mm long, 0.8-0.95 mm wide, ovate-elliptic to broadly elliptic, usually plump, usually purple-tinged. |
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Lower glumes | absent or to 0.1 mm; upper glumes 1-2 mm long, from 3/4 to almost as long as the spikelets, almost glabrous or sparsely to densely pubescent with clavate to capitate hairs (use 20x magnification), glume apices rounded; lower lemmas equaling the spikelets, glabrous or glandular-pubescent, 5-7-veined, veins unequally spaced, outer 3 veins on each side closer to each other than the midvein is to the inner lateral veins; upper lemmas 1.3-2 mm, apiculate, dark brown at maturity; anthers 0.3-0.6 mm. |
absent or to 0.8 mm and acute; upper glumes 1.2-2.4 mm, from 0.8 times as long as to almost equaling the spikelets, glabrous, 3-7-veined, veins usually prominent; lower lemmas 1.5-2.5 mm, usually glabrous, occasionally obscurely puberulent on the margins or, very rarely, distinctly pubescent, 7-veined, veins usually prominent; upper lemmas light brown, gray, and purple. |
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Wipff | , pers. |
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Comm | .). |
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2n | = 36, 54. |
= 36. |
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Digitaria filiformis |
Digitaria abyssinica |
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Distribution |
AL; AR; CT; DC; DE; FL; GA; IA; IL; IN; KS; KY; LA; MA; MD; MI; MO; MS; NC; NH; NJ; NY; OH; OK; PA; RI; SC; TN; TX; VA; VT; WV
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HI |
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Discussion | Digitaria filiformis grows throughout the warmer parts of the eastern United States, van filifomis the most widespread of its varieties, extending into Mexico. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Introduced from Africa, Digitaria abyssinica is not known to be established in the Flora region although it has occasionally been cultivated in the southern United States. It is considered a potentially serious weed threat by the U.S. Department of Agriculture. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 25, p. 364. | FNA vol. 25, p. 372. | ||||||||||||
Parent taxa | Poaceae > subfam. Panicoideae > tribe Paniceae > Digitaria | Poaceae > subfam. Panicoideae > tribe Paniceae > Digitaria | ||||||||||||
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Subordinate taxa | ||||||||||||||
Synonyms | Syntherisma filiformis | |||||||||||||
Name authority | (L.) Koeler | (Hochst. ex A. Rich.) Stapf | ||||||||||||
Web links |