Digitaria ciliaris |
Digitaria cognata |
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fingergrass, Henry's crabgrass, kukaepua'a, saulangi, smooth crabgrass, southern crab grass, tropical crabgrass |
Carolina cottontop, Carolina crabgrass, fall crabgrass, fall witchgrass |
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Habit | Plants annual or of indefinite duration. | Plants perennial; cespitose, without rhizomes. | ||||
Culms | 10-100 cm long, erect portion 30-60 cm, long-decumbent, rooting and branching at the decumbent nodes, sparingly branched or unbranched from the upper nodes; nodes 2-5, glabrous. |
30-56 cm, erect; nodes glabrous. |
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Sheaths | with papillose-based hairs; ligules 2-3.5 mm, erose; blades 1.5-14.4(18.9) cm long, 3-9 mm wide, flat, glabrous, a few scattered papillose-based hairs at the base of the adaxial surfaces (occasionally over the whole adaxial surface), usually also scabrous on both surfaces. |
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Leaves | mainly cauline; sheaths glabrous or sparsely to densely pubescent, sometimes with papillose-based hairs; ligules 0.2-1.5 mm, entire to lacerate; blades 2.4-12.6 cm long, 2-5.4 mm wide, glabrous or pubescent. |
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Panicles | with 2-10 spikelike primary branches, these digitate or in 1-3 whorls on rachises to 2 cm; lowest panicle nodes with hairs more than 0.4 mm; primary branches 3-24 cm long, 0.6-1.2(2) mm wide, glabrous or with less than 1 mm hairs, axes wing-margined, wings at least 1/2 as wide as the midribs, lower and middle portions of the branches bearing spikelets in unequally pedicellate pairs; secondary branches absent; shorter pedicels 0.5-1 mm; longer pedicels 1.5-4 mm. |
simple, 12.8-27.5 cm long, 16.5-44.5 cm wide, open; branches divergent; lower primary branches 10.5-24 cm, often with 1-several sterile branches near the base; pedicels divergent, spikelets solitary. |
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Spikelets | (2.7)2.8-4.1 mm long, homomorphic. |
2.2-3.1 mm long, 0.7-1.1 mm wide, obovate or broadly elliptic. |
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Caryopses | 1.3-1.6 mm. |
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Lower | glumes 0.2-0.8 mm, acute; upper glumes (1.2)1.5-2.7 mm, about 2/3 to almost as long as the spikelet, 3-veined, margins and apices pilose; lower lemmas 2.7-4.1 mm, 7-veined, veins unequally spaced, outer 3 veins crowded together near each margin, well-separated from the midvein, usually smooth, occasionally the lateral veins scabridulous on the distal 1/3 margins and regions between the 2 inner lateral veins hairy, hairs 0.5-1 mm (rarely glabrous), sometimes also with glassy yellow hairs between the 2 inner lateral veins, these more common on the upper spikelets; upper lemmas 2.5-4 mm, glabrous, yellow, tan, or gray when immature, becoming brown, often purple-tinged (occasionally completely purple) at maturity; anthers 0.6-1 mm. |
glumes 0.1-0.8 mm; upper glumes 1.8-2.8 mm, 3(5)-veined, glabrous or pubescent between the veins, hairs appearing as a narrow stripe; lower lemmas similar to the upper glumes in length, texture, and pubescence, 7-veined, veins unequally spaced, lateral veins closer together than the 3 central veins; upper lemmas 1.9-2.9 mm, glabrous, dark brown, narrowly acute; anthers 0.5-0.7 mm, yellow or purple. |
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2n | = 54. |
= 36. |
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Digitaria ciliaris |
Digitaria cognata |
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Distribution |
AL; AR; AZ; CA; CT; DE; FL; GA; IA; IL; IN; KS; KY; LA; MA; MD; MO; MS; NC; NE; NJ; NM; NY; OH; OK; PA; SC; TN; TX; UT; VA; HI; PR; Virgin Islands
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AL; AR; CT; DE; FL; GA; IA; IL; IN; KS; KY; LA; MA; MD; MI; MN; MO; MS; NC; NE; NH; NJ; NY; OH; OK; PA; SC; TN; TX; VA; VT; WI; ON
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Discussion | Digitaria ciliaris is a weedy species, found in open, disturbed areas in most warm-temperate to tropical regions, primarily in the eastern United States. It is particularly abundant in the Southeast. So far as is known, the two varieties distinguished in the following key do not differ in any other characters. They are recognized here pending further study. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Digitaria cognata grows in dry, sandy soils in the eastern portion of the Flora region from southern Ontario and Vermont through the United States and thence to southern Mexico. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 25, p. 382. | FNA vol. 25, p. 362. | ||||
Parent taxa | Poaceae > subfam. Panicoideae > tribe Paniceae > Digitaria | Poaceae > subfam. Panicoideae > tribe Paniceae > Digitaria | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | Leptoloma cognatum | |||||
Name authority | (Retz.) Koeler | (Schult.) Pilg. | ||||
Web links |