Digitaria insularis |
Digitaria sanguinalis |
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sourgrass |
common crabgrass, crabgrass, digitaire sanguine, hairy crab grass |
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Habit | Plants perennial; cespitose, shortly rhizomatous, with knotty bases. | Plants annual. |
Culms | 80-130 cm, erect, with densely villous cataphylls, branching from the lower and middle nodes. |
20-70(112), often decumbent and rooting at the lower nodes. |
Sheaths | usually sparsely to densely papillose-hirsute, occasionally glabrous; ligules 4-6 mm, usually lacerate, not ciliate; blades 20-50 cm long, 10-17 mm wide, lax, smooth or scabridulous abaxially, scabridulous to scabrous adaxially. |
keeled, usually sparsely pubescent with papillose-based hairs; ligules 0.5-2.6 mm; blades 2-11(14) cm long, 3-8(12) mm wide, usually with papillose-based hairs on both surfaces, sometimes glabrous. |
Panicles | 20-35 cm long, 2-10 cm wide, with numerous spikelike primary branches; primary branches 10-15 cm, appressed to ascending at maturity, axes not wing-margined or with wings less than 1/2 as wide as the midribs; internodes 3-4.5(6) mm (midbranch), bearing spikelets in unequally pedicellate pairs; secondary branches rarely present; pedicels not adnate to the branches; shorter pedicels 0.7-2 mm; longer pedicels 2.5-5 mm; terminal pedicels 2-5 mm. |
with 4-13 spikelike primary branches, these subdigitate or on rachises to 6 cm; primary branches 3-30 cm long, 0.7-1.5 mm wide, flattened and winged, wings more than 1/2 as wide as the midribs, lower and middle portion of the branches bearing spikelets in unequally pedicellate pairs, pedicels not adnate to the branches; secondary branches rarely present. |
Spikelets | 5.5-8.2 mm (including pubescence), 4.2-5.9 mm (excluding pubescence), narrowly ovate, acuminate. |
homomorphic, 1.7-3.4 mm long, 0.7-1.1 mm wide. |
Lower | glumes 0.6-0.8 mm; upper glumes 3.5-4.5 mm, 3-5-veined, pubescent on the margins; lower lemmas 4.1-5.7 mm (exceeded 1.5-5 mm by pubescence), narrowly ovate, 7-veined, pubescent between most, sometimes all, of the veins and on the margins, veins usually obscured by a dense covering of golden-brown hairs, hairs 3-6 mm, spreading at maturity, intercostal regions on either side of the midvein glabrous or pubescent with shorter, fine, white hairs, sometimes intermixed with the golden-brown hairs; upper lemmas 3.2-4.5 mm, narrowly ovate, brown when immature, dark brown at maturity, acuminate; anthers 1-1.2 mm. |
glumes 0.2-0.4 mm long, veinless; upper glumes 0.9-2 mm, 1/3 – 1/2 as long as the spikelets, 3-veined, pubescent on the margins; lower lemmas usually exceeded or equaled by the upper florets, sometimes exceeding them but by no more than 0.2 mm, glabrous, 7-veined, lateral (or all) veins scabrous throughout or smooth on the lower (1/3)1/2 and scabrous distally, 3 middle veins usually widely spaced, remaining veins on each side close together and near the margins; upper lemmas 1.7-3 mm, yellow or gray, frequently purple-tinged when immature, often becoming brown at maturity; anthers 0.5-0.9 mm. |
2n | = 36. |
= 36, 28, 34, 54. |
Digitaria insularis |
Digitaria sanguinalis |
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Distribution |
AL; AZ; FL; IL; MS; TX; HI; PR; Virgin Islands
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AL; AR; AZ; CA; CO; CT; DC; DE; 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; PR; AB; BC; MB; NS; ON; PE; QC; SK
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Discussion | Digitaria insularis grows in low, open ground of the southern United States, and extends to the West Indies, Mexico, and through Central America to Argentina. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Digitaria sanguinalis is a weedy Eurasian species that is now found in waste ground of fields, gardens, and lawns throughout much of the world, including the Flora region. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 25, p. 370. | FNA vol. 25, p. 380. |
Parent taxa | Poaceae > subfam. Panicoideae > tribe Paniceae > Digitaria | Poaceae > subfam. Panicoideae > tribe Paniceae > Digitaria |
Sibling taxa | ||
Synonyms | Trichachne insularis | Syntherisma sanguinalis |
Name authority | (L.) Mez ex Ekman | (L.) Scop. |
Web links |
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