Digitaria ischaemum |
Digitaria sanguinalis |
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digitaire astringente, smooth crab grass |
common crabgrass, crabgrass, digitaire sanguine, hairy crab grass |
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Habit | Plants annual or of indefinite duration. | Plants annual. |
Culms | 20-55(70) cm, decumbent, branching and rooting at the lower nodes; nodes 3-4. |
20-70(112), often decumbent and rooting at the lower nodes. |
Sheaths | glabrous or sparsely pubescent; ligules 0.6-2.5 mm; blades 1.5-9 cm long, 3-5 mm wide, glabrous, with a few papillose-based hairs basally. |
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 | terminal and axillary; terminal panicles with 2-7 spikelike primary branches, subdigitate or on 0.5-2 cm rachises; primary branches 6-15.5 cm, axes wing-margined, wings at least 1/2 as wide as the midribs, bearing spikelets in groups of 3, lower portions of the longer pedicels adnate to the axes; secondary branches rarely present; axillary inflorescences always present in some of the lower sheaths, entirely or partially concealed. |
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 | 1.7-2.3 mm, homomorphic, narrowly elliptic. |
homomorphic, 1.7-3.4 mm long, 0.7-1.1 mm wide. |
Lower glumes | absent or a veinless, membranous rim; upper glumes 1.3-2.3 mm, from 3/4 as long as to equaling the upper lemmas, appressed-pubescent; lower lemmas 1.7-2.3 mm, 7-veined, veins unequally spaced, smooth, pubescent; upper lemmas dark brown at maturity; anthers 0.4-0.6 mm. |
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 ischaemum |
Digitaria sanguinalis |
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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; PR; AB; BC; MB; NB; NS; ON; PE; QC; SK; 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 ischaemum is a Eurasian weed that is now common in lawns, gardens, fields, and waste ground in warm-temperate regions throughout the world, including much of the Flora region. Larger plants with 5-7 inflorescence branches 8-15 cm long have been called var. mississippiensis (Gatt.) Fernald, but they intergrade with more typical plants, and so do not merit taxonomic recognition. (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. 372. | FNA vol. 25, p. 380. |
Parent taxa | Poaceae > subfam. Panicoideae > tribe Paniceae > Digitaria | Poaceae > subfam. Panicoideae > tribe Paniceae > Digitaria |
Sibling taxa | ||
Synonyms | Syntherisma linearis, Syntherisma ischaemum | Syntherisma sanguinalis |
Name authority | (Schreb.) Muhl. | (L.) Scop. |
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