Urochloa arizonica

(Scribn. & Merr.) Morrone & Zuloaga
Common names: Arizona signalgrass
Synonyms: Panicum arizonicum Brachiaria arizonica
Treatment appears in FNA Volume 25. Treatment on page 495.

Plants annual. Culms 15-65 cm, erect or geniculate, branching from the lower nodes; nodes glabrous or hispid. Sheaths glabrous or with papillose-based hairs, margins ciliate distally; ligules 1-1.6 mm; blades 5-15 cm long, 5-12 mm wide, glabrous. Panicles 6-20 cm long, 2-5 cm wide, ovoid, with 6-12 spikelike primary branches in more than 2 ranks; primary branches 3-7 cm, divergent, axes about 0.4 mm wide, triquetrous, densely pubescent with papillose-based hairs; secondary branches short, divergent; pedicels shorter than the spikelets, with papillose-based hairs. Spikelets 3.2-4 mm long, 1.2-1.6 mm wide, mostly paired, in 2 rows, appressed to the branches. Glumes scarcely separate, rachilla internodes short, not pronounced; lower glumes 1.5-2 mm, to 1/2 as long as the spikelets, glabrous, 5-veined, sometimes with evident cross venation near the apices; upper glumes 2.5-3.2 mm, glabrous or shortly hirsute, 7-veined, with evident cross venation distally; lower florets staminate or sterile; lower lemmas 2.5-3.2 mm, glabrous or shortly hirsute, 5-veined, about as long as the spikelet; lower paleas present; upper lemmas 2.8-3 mm long, 1.2-1.6 mm wide, acute, beaked or mucronate; anthers 0.8-1 mm. Caryopses 1.5-2 mm; hila punctiform. 2n = 36.

Distribution

N.Mex., Tex., Calif., Ala., Miss., Ariz., Fla.

Discussion

Urochloa arizonica is native to the southwestern United States and northern Mexico, but has been introduced to, and appears to be established in, the southeastern United States. It grows in open, dry areas with rocky or sandy soils.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number."elongated" is not a number.

... more about "Urochloa arizonica"
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
anatomy +  and kranz +
J.K. Wipff +  and Rahmona A. Thompson +
(Scribn. & Merr.) Morrone & Zuloaga +
1 (?) +  and 3 (?) +
triquetrous +
keeled +  and rounded +
pseudopetiolate +  and branching +
divergent +  and parallel +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
membranous +
disarticulating +  and pseudopetiolate +
non-radiate +  and radiate +
5 cm50 mm <br />0.05 m <br /> (15 cm150 mm <br />0.15 m <br />) +
ovatelanceolate +  and lanceolate +
5mm;12mm +
spikelike +
not developed +
compressed +, ovoid +  and elliptic +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
sometimes longer +
Arizona signalgrass +
geniculate +
15 cm150 mm <br />0.15 m <br /> (65 cm650 mm <br />0.65 m <br />) +
N.Mex. +, Tex. +, Calif. +, Ala. +, Miss. +, Ariz. +  and Fla. +
1/2 +  and 3/4 +
capillary +
germination +
pistillate +  and staminate +
sometimes longer +
compressed +  and terete +
shorter or longer +
subtending +
unequal +
membranous +
papillose-based +
uncinate +
bracteate +  and ebracteate +
solid +  and hollow +
cauline +  and basal +
coriaceous +
0.1 cm1 mm <br />0.001 m <br /> (0.16 cm1.6 mm <br />0.0016 m <br />) +
membranous +
inconspicuous +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
hirsute +  and glabrous +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.32 cm3.2 mm <br />0.0032 m <br />) +
complex +  and simple +
concealed +  and prominent +
hispid +  and glabrous +
2 +  and 1 +
6cm +  and 20cm +
subterranean +
2 cm20 mm <br />0.02 m <br /> (5 cm50 mm <br />0.05 m <br />) +
dry +  and fleshy +
3 cm30 mm <br />0.03 m <br /> (7 cm70 mm <br />0.07 m <br />) +
with papillose-based hairs +  and glabrous +
pedicellate +  and subsessile +
well-developed +
0.32 cm3.2 mm <br />0.0032 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
1 +  and 60 +
unisexual +  and bisexual +
compressed +, ovoid +  and ellipsoid +
1.2mm +  and 1.6mm +
1 (?) +  and 3 (?) +
fused +  and free +
2 (?) +  and 3 (?) +
dome--shaped +  and triangular +
Panicum arizonicum +  and Brachiaria arizonica +
Urochloa arizonica +
Urochloa +
species +
membranous +
not disarticulating +, sessile +  and (0)1-11-veined +
acuminate +, mucronate +, planoconvex +, ovoid +  and ellipsoid +
hirsute +  and glabrous +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.32 cm3.2 mm <br />0.0032 m <br />) +
0.28 cm2.8 mm <br />0.0028 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
verrucose +  and rugose +
mucronate +, beaked +  and acute +
1.2mm +  and 1.6mm +
lustrous +  and shiny +
aquatic +  and terrestrial +
dioecious +, monoecious +  and synoecious +
10 +, 9 +, 8 +  and 7 +