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sourgrass

velvet crabgrass

Habit Plants perennial; cespitose, shortly rhizomatous, with knotty bases. Plants of indefinite duration; loosely cespitose to straggling.
Culms

80-130 cm, erect, with densely villous cataphylls, branching from the lower and middle nodes.

15-80 m, decumbent, rooting and branching 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.

pilose, with papillose-based hairs;

ligules 1.8-2 mm;

blades 4-15 cm long, 3-10 mm wide, pilose, with papillose-based hairs.

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 5-18 spikelike primary branches on 2.5-5 cm rachises, lower branches usually verticillate;

primary branches 3.5-10 cm long, 0.3-0.5 mm wide, narrowly wing-margined, wings less than 1/2 as wide as the midribs, bearing spikelets in unequally pedicellate pairs;

secondary branches often present, often highly divergent;

shorter pedicels 0.2-0.5 mm;

longer pedicels 0.8-1.1 mm.

Spikelets

5.5-8.2 mm (including pubescence), 4.2-5.9 mm (excluding pubescence), narrowly ovate, acuminate.

1.5-2 mm long, about 0.5 mm wide, elliptic-lanceolate.

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 absent or to 0.2 mm;

upper glumes 1.5-1.7 mm, usually to 3/4 as long as the spikelets, 3-veined, villous between the veins, hairs tapering or parallel-sided;

lower lemmas about as long as the spikelets, 7-veined, veins unequally spaced, 2 veins crowded together near each margin, 3 inner veins well-separated, pubescent on the margins and between the inner lateral veins, hairs about 0.2 mm, sometimes sparse, lateral veins smooth throughout or scabridulous only on the distal 1/3;

upper lemmas 1.5-1.7 mm, usually gray at maturity, sometimes brown;

anthers about 0.5 mm.

2n

= 36.

= 18.

Digitaria insularis

Digitaria velutina

Distribution
from FNA
AL; AZ; FL; IL; MS; TX; HI; PR; Virgin Islands
[WildflowerSearch map]
[BONAP county map]
from FNA
TX
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 velutina is an African species, appearing on the noxious weed list of the U.S. Department of Agriculture. It has been erroneously reported as occurring in Texas (Kartesz and Meacham 1999).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 25, p. 370. FNA vol. 25, p. 378.
Parent taxa Poaceae > subfam. Panicoideae > tribe Paniceae > Digitaria Poaceae > subfam. Panicoideae > tribe Paniceae > Digitaria
Sibling taxa
D. abyssinica, D. arenicola, D. bakeri, D. bicornis, D. californica, D. ciliaris, D. cognata, D. didactyla, D. eriantha, D. filiformis, D. floridana, D. gracillima, D. hitchcockii, D. horizontalis, 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
D. abyssinica, D. arenicola, D. bakeri, D. bicornis, D. californica, D. ciliaris, D. cognata, 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. violascens
Synonyms Trichachne insularis
Name authority (L.) Mez ex Ekman (Forssk.) P. Beauv.
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