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fingergrass, Henry's crabgrass, kukaepua'a, saulangi, smooth crabgrass, southern crab grass, tropical crabgrass

violet crabgrass

Habit Plants annual or of indefinite duration. Plants annual or of indefinite duration.
Culms

10-100 cm long, erect portion 30-60 cm, long-decumbent, rooting and branching at the decumbent nodes, sparingly branched or unbranched from the upper nodes;

nodes 2-5, glabrous.

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

nodes 3-4.

Sheaths

with papillose-based hairs;

ligules 2-3.5 mm, erose;

blades 1.5-14.4(18.9) cm long, 3-9 mm wide, flat, glabrous, a few scattered papillose-based hairs at the base of the adaxial surfaces (occasionally over the whole adaxial surface), usually also scabrous on both surfaces.

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.

Panicles

with 2-10 spikelike primary branches, these digitate or in 1-3 whorls on rachises to 2 cm;

lowest panicle nodes with hairs more than 0.4 mm;

primary branches 3-24 cm long, 0.6-1.2(2) mm wide, glabrous or with less than 1 mm hairs, axes wing-margined, wings at least 1/2 as wide as the midribs, lower and middle portions of the branches bearing spikelets in unequally pedicellate pairs;

secondary branches absent;

shorter pedicels 0.5-1 mm;

longer pedicels 1.5-4 mm.

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.

Spikelets

(2.7)2.8-4.1 mm long, homomorphic.

1.2-1.7 mm, homomorphic, narrowly elliptic.

Lower

glumes 0.2-0.8 mm, acute;

upper glumes (1.2)1.5-2.7 mm, about 2/3 to almost as long as the spikelet, 3-veined, margins and apices pilose;

lower lemmas 2.7-4.1 mm, 7-veined, veins unequally spaced, outer 3 veins crowded together near each margin, well-separated from the midvein, usually smooth, occasionally the lateral veins scabridulous on the distal 1/3 margins and regions between the 2 inner lateral veins hairy, hairs 0.5-1 mm (rarely glabrous), sometimes also with glassy yellow hairs between the 2 inner lateral veins, these more common on the upper spikelets;

upper lemmas 2.5-4 mm, glabrous, yellow, tan, or gray when immature, becoming brown, often purple-tinged (occasionally completely purple) at maturity;

anthers 0.6-1 mm.

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.

2n

= 54.

= 36.

Digitaria ciliaris

Digitaria violascens

Distribution
from FNA
AL; AR; AZ; CA; CT; DE; FL; GA; IA; IL; IN; KS; KY; LA; MA; MD; MO; MS; NC; NE; NJ; NM; NY; OH; OK; PA; SC; TN; TX; UT; VA; HI; PR; Virgin Islands
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; AR; FL; GA; IN; KY; LA; MA; MS; NC; OK; SC; TN; TX; HI; PR
[WildflowerSearch map]
[BONAP county map]
Discussion

Digitaria ciliaris is a weedy species, found in open, disturbed areas in most warm-temperate to tropical regions, primarily in the eastern United States. It is particularly abundant in the Southeast. So far as is known, the two varieties distinguished in the following key do not differ in any other characters. They are recognized here pending further study.

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

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.)

Key
1. Lower lemmas without glassy yellow hairs
var. ciliaris
1. Lower lemmas with glassy yellow hairs
var. chrysoblephara
Source FNA vol. 25, p. 382. FNA vol. 25, p. 372.
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. 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. 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. velutina
Subordinate taxa
D. ciliaris var. chrysoblephara, D. ciliaris var. ciliaris
Name authority (Retz.) Koeler Link
Web links