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Carolina cottontop, Carolina crabgrass, fall crabgrass, fall witchgrass

Habit Plants perennial; cespitose, without rhizomes.
Culms

30-56 cm, erect;

nodes glabrous.

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.

Panicles

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.

Spikelets

2.2-3.1 mm long, 0.7-1.1 mm wide, obovate or broadly elliptic.

Lower 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.

Caryopses

1.3-1.6 mm.

2n

= 36.

Digitaria cognata

Distribution
from FNA
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 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.)

Source FNA vol. 25, p. 362.
Parent taxa Poaceae > subfam. Panicoideae > tribe Paniceae > Digitaria
Sibling taxa
D. abyssinica, D. arenicola, D. bakeri, D. bicornis, D. californica, D. ciliaris, D. didactyla, D. eriantha, D. filiformis, D. floridana, D. gracillima, D. hitchcockii, D. horizontalis, D. insularis, D. ischaemum, D. leucocoma, D. longiflora, D. milanjiana, D. nuda, D. patens, D. pauciflora, D. pubiflora, D. sanguinalis, D. serotina, D. setigera, D. simpsonii, D. texana, D. tomentosa, D. velutina, D. violascens
Synonyms Leptoloma cognatum
Name authority (Schult.) Pilg.
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