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violet crabgrass

slender crabgrass

Habit Plants annual or of indefinite duration. Plants annual, or short-lived perennials; cespitose, not rhizomatous.
Culms

15-60 cm, erect, usually not branching from the upper nodes;

nodes 3-4.

(10)25-150 cm, erect or decumbent, branching, sometimes rooting at the lower nodes;

nodes 3-6.

Sheaths

glabrous or sparsely pubescent;

ligules 0.6-2.5 mm;

blades 1.5-9 cm long, 3-5 mm wide, glabrous, with papillose-based hairs basally.

keeled, basal sheaths usually with papillose-based hairs, rarely glabrous;

ligules 0.3-1.5 mm;

blades 2-18 cm long, 1-6 mm wide, flat or involute, glabrous, scabrous, or pilose.

Panicles

with 2-7 spikelike primary branches in 1-2 verticils;

primary branches 3-12 cm, erect to ascending, axes 0.6-1 mm wide, wing-margined, wings at least 1/2 as wide as the midribs, lower and middle portions of the branches bearing spikelets in groups of 3(4, 5);

secondary branches rarely present;

axillary inflorescences absent.

with 2-7 spikelike primary branches, these digitate or the rachises to 1 cm;

longest primary branches 20-25 cm, axes triquetrous, not winged, with spikelets in unequally pedicellate groups of 3(-5) on the basal ½ (J.

Spikelets

1.2-1.7 mm, homomorphic, narrowly elliptic.

1.3-2.8 mm.

Lower glumes

absent or a veinless, membranous rim;

upper glumes 1.2-1.4 mm, 1/2 as long as to almost equaling the upper lemmas, 3-veined, appressed-pubescent, hairs minutely verrucose;

lower lemmas 1.2-1.7 mm, 5-7-veined, veins equally spaced, region between the 2 inner lateral veins and the margins appressed-pubescent, hairs 0.3-0.5 mm, smooth or minutely verrucose (use 50x magnification), verrucose hairs most abundant near the lemma bases;

upper lemmas light brown when immature, dark brown at maturity;

anthers 0.4-0.6 mm.

absent or to 0.1 mm;

upper glumes 1-2 mm long, from 3/4 to almost as long as the spikelets, almost glabrous or sparsely to densely pubescent with clavate to capitate hairs (use 20x magnification), glume apices rounded;

lower lemmas equaling the spikelets, glabrous or glandular-pubescent, 5-7-veined, veins unequally spaced, outer 3 veins on each side closer to each other than the midvein is to the inner lateral veins;

upper lemmas 1.3-2 mm, apiculate, dark brown at maturity;

anthers 0.3-0.6 mm.

Wipff

, pers.

Comm

.).

2n

= 36.

= 36, 54.

Digitaria violascens

Digitaria filiformis

Distribution
from FNA
AL; AR; FL; GA; IN; KY; LA; MA; MS; NC; OK; SC; TN; TX; HI; PR
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; AR; CT; DC; DE; FL; GA; IA; IL; IN; KS; KY; LA; MA; MD; MI; MO; MS; NC; NH; NJ; NY; OH; OK; PA; RI; SC; TN; TX; VA; VT; WV
[WildflowerSearch map]
[BONAP county map]
Discussion

Digitaria violascens is a weedy species that is native to tropical regions of the Eastern Hemisphere. It is now established in the Flora region, primarily in the south-eastern United States, and in Mexico and Central America. It grows in disturbed sites.

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

Digitaria filiformis grows throughout the warmer parts of the eastern United States, van filifomis the most widespread of its varieties, extending into Mexico.

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

Key
1. Lower lemmas glabrous
var. laeviglumis
1. Lower lemmas pubescent.
→ 2
2. Basal leaf sheaths glabrous; cauline blades about 1 mm wide, folded or involute
var. dolichophylla
2. Basal leaf sheaths with papillose-based hairs; cauline blades 1-6 mm wide, flat.
→ 3
3. Spikelets 1.3-1.9 mm long; panicle branches 3-13 cm long; culms 10-80 cm tall
var. filiformis
3. Spikelets 2-2.8 mm long; panicle branches 10-25 cm long; plants 75-150 cm tall
var. villosa
Source FNA vol. 25, p. 372. FNA vol. 25, p. 364.
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. 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. abyssinica, D. arenicola, D. bakeri, D. bicornis, D. californica, D. ciliaris, D. cognata, D. didactyla, D. eriantha, 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
Subordinate taxa
D. filiformis var. dolichophylla, D. filiformis var. filiformis, D. filiformis var. laeviglumis, D. filiformis var. villosa
Synonyms Syntherisma filiformis
Name authority Link (L.) Koeler
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