Digitaria horizontalis

Willd.
Introduced
Treatment appears in FNA Volume 25. Treatment on page 378.

Plants of indefinite duration; sprawling. Culms to 1 m, erect portion 20-25 cm, decumbent, rooting and branching freely at the nodes. Sheaths usually with scattered papillose-based hairs, hairs more abundant on the lower sheaths; ligules 1.5-1.8 mm, erose; blades 3-14 cm long, 3-9 mm wide, evenly, often densely pubescent adaxially, hairs papillose-based. Panicles with 2-14 spikelike branches attached to 4-15 cm rachises, lower branches whorled, upper branches often paired or solitary; lower nodes with hairs more than 0.4 mm; primary branches 4-12 cm, axes 0.4-0.7 mm wide, wing-margined, wings at least 1/2 as wide as the midribs, often with scattered 1-4 mm hairs proximally, bearing spikelets in unequally pedicellate pairs on the proximal and middle portion of the branches; secondary branches rarely present; shorter pedicels 0.3-0.5 mm; longer pedicels 1.3-2 mm. Spikelets homomorphic, 2.1-2.4 mm, narrowly ovate. Lower glumes 0.1-0.2 mm; upper glumes 1-1.1 mm, 1/3 – 1/2 as long as the spikelets, 3-veined, margins and apices ciliate; lower lemmas about as long as the spikelets, lanceolate, 7-veined, lateral 3 veins on each side unequally or equally spaced, smooth or scabrous over the distal 1/3, lemma margins and the region between the second and third veins densely pubescent, hairs 0.05-0.1 mm, white; upper lemmas slightly shorter than the lower lemmas, yellowish or grayish when immature, becoming light-brown at maturity, minutely striate. Caryopses about 1.8 mm, tan. 2n = 36.

Distribution

Puerto Rico, Virgin Islands, Ala., Pacific Islands (Hawaii), Miss., S.C., Fla.

Discussion

Digitaria horizontalis is native to tropical regions of the Americas. It has been found in hammocks and disturbed areas in central and southern Florida and at a few other locations in the southeastern United States, including bal¬last dumps in Mobile, Alabama. It is probably a recent introduction to the Flora region, even in Florida.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

... more about "Digitaria horizontalis"
obtuse +  and acuminate +
anatomy +  and kranz +
J.K. Wipff +
Willd. +
1 (?) +  and 3 (?) +
wing-margined +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.07 cm0.7 mm <br />7.0e-4 m <br />) +
keeled +  and rounded +
pseudopetiolate +  and branching +
divergent +  and parallel +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
membranous +
disarticulating +  and pseudopetiolate +
non-radiate +  and radiate +
3 cm30 mm <br />0.03 m <br /> (14 cm140 mm <br />0.14 m <br />) +
usually linear +  and lanceolate occasionally ovate +
0.3 cm3 mm <br />0.003 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
triquetrous +
spikelike +
0 cm0 mm <br />0 m <br /> (1 cm10 mm <br />0.01 m <br />) +
not developed +
planoconvex +
1.8 cm18 mm <br />0.018 m <br /> (?) +
sometimes longer +
at aerial culm nodes +  and branching +
decumbent +  and erect +
0 cm0 mm <br />0 m <br /> (100 cm1,000 mm <br />1 m <br />) +
Puerto Rico +, Virgin Islands +, Ala. +, Pacific Islands (Hawaii) +, Miss. +, S.C. +  and Fla. +
1/5 +  and 1/2 +
capillary +
germination +
pistillate +  and staminate +
sometimes longer +
compressed +  and terete +
shorter or longer +
subtending +
unequal +
membranous +
papillose-based +
uncinate +
0.005 cm0.05 mm <br />5.0e-5 m <br /> (0.01 cm0.1 mm <br />1.0e-4 m <br />) +
bracteate +  and ebracteate +
solid +  and hollow +
cauline +  and basal +
coriaceous +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.18 cm1.8 mm <br />0.0018 m <br />) +
membranous +
inconspicuous +
0.13 cm1.3 mm <br />0.0013 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.02 cm0.2 mm <br />2.0e-4 m <br />) +
complex +  and simple +
concealed +  and prominent +
2 +  and 1 +
pedicellate +
subterranean +
dry +  and fleshy +
branching +  and rooting +
20 cm200 mm <br />0.2 m <br /> (25 cm250 mm <br />0.25 m <br />) +
4 cm40 mm <br />0.04 m <br /> (12 cm120 mm <br />0.12 m <br />) +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
Introduced +
in triplets +  and paired +
1 +  and 60 +
unisexual +  and bisexual +
0.21 cm2.1 mm <br />0.0021 m <br /> (0.24 cm2.4 mm <br />0.0024 m <br />) +
1 +  and 3 +
fused +  and free +
2 +  and 3 +
dome--shaped +  and triangular +
Gramineae +
Digitaria horizontalis +
Digitaria +
species +
membranous +
solitary +  and paired +
1/3 +  and 1/2 +
0.1 cm1 mm <br />0.001 m <br /> (0.11 cm1.1 mm <br />0.0011 m <br />) +
light-brown +, grayish +  and yellowish +
cartilaginous +, coriaceous +  and indurate +
perennial +  and annual +
aquatic +  and terrestrial +
dioecious +, monoecious +  and synoecious +