Urochloa brizantha

(Hochst. ex A. Rich.) R.D. Webster
Common names: Palisade signalgrass
Synonyms: Brachiaria brizantha
Treatment appears in FNA Volume 25. Treatment on page 499.

Plants perennial; shortly rhizomatous. Culms (30) 100-200 cm, erect or geniculately ascending, occasionally branched; nodes glabrous. Sheaths glabrous or pubescent between the veins, margins glabrous; collars glabrous; ligules 1-2.2 mm; blades 9-40 cm long, 6-20 mm wide, glabrous or hispidulous on both surfaces, margins usually ciliate basally. Panicles 3-20 cm long, 2.5-3 cm wide, with 1-7 (16) spikelike primary branches in 2 ranks; rachises scabrous and pubescent; primary branches 4-16 (20) cm, ascending to divergent, axils glabrous, axes 0.5-1.2 mm wide, narrowly winged and crescentric (the margins inrolled to produce a crescent-shaped cross-section), mostly scabrous, margins ciliate with papillose-based hairs; secondary branches absent, pedicels shorter than the spikelets, glabrous, scabrous. Spikelets 4-6 mm long, 1.8-2.2 mm wide, ovoid to ellipsoid, with 0.3-0.5 mm calluses, solitary, in 1 row (rarely in 2 rows at the base of the lower branches), appressed to the branches. Glumes separated by about 0.5 mm; lower glumes 1.8-3.3 mm long, about 1/3 as long as the spikelets, 7-11-veined; upper glumes 3.6-5.9 mm, 7-veined, glabrous or pubescent, without evident cross venation; lower florets staminate; lower lemmas 3.8-5.8 mm, glabrous or pubescent, 5-veined; lower paleas present; upper lemmas 3.3-5.6 mm long, 1.6-2 mm wide, ellipsoid, apices acute, mucronate; anthers about 2.2-2.5 mm. 2n = 18, 36, 54.

Discussion

Urochloa brizantha, a native of tropical Africa, was first reported from the Flora region in 1993 (Fox and Hatch 1995). It is considered a sporadic introduction in the Flora area.

Clayton and Renvoize (1982) report that Urochloa brizantha intergrades with U. decumbens (Stapf) R.D. Webster, and intermediates are often difficult to separate, although they do not seem to be very common in the wild. The forms widely introduced throughout the tropics as forage were selected from among these intermediates. The selection most commonly used as a forage has the inflorescence characters of U. brizantha and the habit features of U. decumbens. Davidse and Pohl (1994) reported that the material introduced into Mesoamerica is referable to U. decumbens. Although U. decumbens has not been reported in the Flora area, it is expected in Florida, because it is widely used as forage in the tropics. The two taxa can be distinguished by their panicle branches: Urochloa decumbens has flat, ribbonlike panicle branches 1-1.8 mm wide, whereas U. brizantha has crescentric panicle branches 0.5-1.2 mm wide.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

... more about "Urochloa brizantha"
54 +, 36 +  and 18 +
0.22 cm2.2 mm <br />0.0022 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
mucronate +  and acute +
anatomy +  and kranz +
J.K. Wipff +  and Rahmona A. Thompson +
(Hochst. ex A. Rich.) R.D. Webster +
1 (?) +  and 3 (?) +
triquetrous +  and flat +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 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 +
9 cm90 mm <br />0.09 m <br /> (40 cm400 mm <br />0.4 m <br />) +
hispidulous +  and glabrous +
ovatelanceolate +  and lanceolate +
0.6 cm6 mm <br />0.006 m <br /> (2 cm20 mm <br />0.02 m <br />) +
spikelike +
0 cm0 mm <br />0 m <br /> (1 cm10 mm <br />0.01 m <br />) +
not developed +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
compressed +, ovoid +  and elliptic +
sometimes longer +
Palisade signalgrass +
ascending +  and erect +
geniculate +
100 cm1,000 mm <br />1 m <br /> (200 cm2,000 mm <br />2 m <br />) +
Puerto Rico +  and Tex. +
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 /> (0.22 cm2.2 mm <br />0.0022 m <br />) +
membranous +
inconspicuous +
0.18 cm1.8 mm <br />0.0018 m <br /> (0.33 cm3.3 mm <br />0.0033 m <br />) +
pubescent +  and glabrous +
0.38 cm3.8 mm <br />0.0038 m <br /> (0.58 cm5.8 mm <br />0.0058 m <br />) +
complex +  and simple +
concealed +  and prominent +
2 +  and 1 +
3cm +  and 20cm +
subterranean +
2.5 cm25 mm <br />0.025 m <br /> (3 cm30 mm <br />0.03 m <br />) +
dry +  and fleshy +
20 cm200 mm <br />0.2 m <br /> (?) +
4 cm40 mm <br />0.04 m <br /> (16 cm160 mm <br />0.16 m <br />) +
pubescent +  and glabrous +
pedicellate +  and subsessile +
divergent +  and paired +
well-developed +
0.4 cm4 mm <br />0.004 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
1 +  and 60 +
unisexual +  and bisexual +
ovoid +  and ellipsoid +
1.8mm +  and 2.2mm +
1 +  and 3 +
fused +  and free +
2 +  and 3 +
dome--shaped +  and triangular +
Brachiaria brizantha +
Urochloa brizantha +
Urochloa +
species +
membranous +
not disarticulating +, sessile +  and (0)1-11-veined +
acuminate +, mucronate +, planoconvex +, ovoid +  and ellipsoid +
pubescent +  and glabrous +
0.36 cm3.6 mm <br />0.0036 m <br /> (0.59 cm5.9 mm <br />0.0059 m <br />) +
0.33 cm3.3 mm <br />0.0033 m <br /> (0.56 cm5.6 mm <br />0.0056 m <br />) +
verrucose +  and rugose +
1.6mm +  and 2mm +
lustrous +  and shiny +
aquatic +  and terrestrial +
dioecious +, monoecious +  and synoecious +
10 +, 9 +, 8 +  and 7 +