Cenchrus brownii

Roem. & Schult.
Common names: Slimbristle sandbur Green sandbur
Treatment appears in FNA Volume 25. Treatment on page 531.
Revision as of 03:14, 30 July 2020 by imported>Volume Importer
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Plants annual. Culms 25-100 cm, erect or decumbent. Sheaths slightly compressed; ligules 0.6-1.3 mm; blades 6-30 cm long, 0.4-1.1 cm wide, adaxial surfaces glabrous or sparsely pilose. Panicles 4-15 cm; rachis internodes 0.8-1.7 mm; fascicles 5-8 mm long, 2-A. 5 mm wide, imbricate, globose, villous at the base, tawny; outer bristles 5-25, the majority equaling or slightly exceeding the inner bristles but narrower and terete, arising in a whorl at the base of the fascicles; inner bristles 4-10, 2-4 mm long, 0.6-1.8 mm wide at the base, flattened, not grooved, erect or interlocking at maturity, fused for 1/3 their length or more, forming a globose cupule. Spikelets 2-3 per fascicle, 3-6 mm. Lower glumes 0.5-2.5 mm; upper glumes 2.2-4.9 mm, 3-5-veined; lower lemmas 3-5.5 mm; upper florets 3.6-5.4 mm; anthers 0.8-2.3 mm. Caryopses 1.9-2.6 mm long, 0.8-1.9 mm wide, ovoid. 2n = 34.

Distribution

Puerto Rico, Tex., Virgin Islands, N.C., Ala., Ga., Fla.

Discussion

Cenchrus brownii is native to sandy waste places and forest borders. It occurs infrequently on the coastal plain of the southeastern United States, but is common through the Caribbean, Central America, and the northern coast of South America. It has also been introduced to other parts of the world. The record from Texas may represent an introduction; only one specimen is known from the state.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

... more about "Cenchrus brownii"
pilose +  and glabrous +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.23 cm2.3 mm <br />0.0023 m <br />) +
anatomy +  and kranz +
Michael T. Stieber +  and J.K. Wipff +
Roem. & Schult. +
1 (?) +  and 3 (?) +
keeled +  and rounded +
pseudopetiolate +  and branching +
divergent +  and parallel +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
membranous +
disarticulating +  and pseudopetiolate +
non-radiate +  and radiate +
6 cm60 mm <br />0.06 m <br /> (30 cm300 mm <br />0.3 m <br />) +
folded +  and flat +
0.4 cm4 mm <br />0.004 m <br /> (1.1 cm11 mm <br />0.011 m <br />) +
spikelike +
reduced +
0 cm0 mm <br />0 m <br /> (1 cm10 mm <br />0.01 m <br />) +
scabridulous +
not developed +
0.19 cm1.9 mm <br />0.0019 m <br /> (0.26 cm2.6 mm <br />0.0026 m <br />) +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.19 cm1.9 mm <br />0.0019 m <br />) +
Slimbristle sandbur +  and Green sandbur +
branched +  and solid +
decumbent +  and erect +
geniculate +
25 cm250 mm <br />0.25 m <br /> (100 cm1,000 mm <br />1 m <br />) +
Puerto Rico +, Tex. +, Virgin Islands +, N.C. +, Ala. +, Ga. +  and Fla. +
capillary +
germination +
pistillate +  and staminate +
sometimes longer +
compressed +  and terete +
shorter or longer +
subtending +
unequal +
membranous +
uncinate +
bracteate +  and ebracteate +
2mm +  and 4mm +
0.6mm +  and 1.8mm +
solid +  and hollow +
cauline +  and basal +
coriaceous +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.13 cm1.3 mm <br />0.0013 m <br />) +
membranous +
inconspicuous +
acute +  and acuminate +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (0.55 cm5.5 mm <br />0.0055 m <br />) +
purplish +  and tawny +
scabridulous +
complex +  and simple +
concealed +  and prominent +
2 +  and 1 +
slightly exceeding the inner bristles +  and equaling +
subterranean +
4 cm40 mm <br />0.04 m <br /> (15 cm150 mm <br />0.15 m <br />) +
dry +  and fleshy +
imbricate +  and fascicles +
0.5 cm5 mm <br />0.005 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.17 cm1.7 mm <br />0.0017 m <br />) +
compressed +
in triplets +  and paired +
unisexual +  and bisexual +
compressed +  and terete +
0.3 cm3 mm <br />0.003 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
1 +  and 3 +
fused +  and free +
2 +  and 3 +
dome--shaped +  and triangular +
Gramineae +
Cenchrus brownii +
Cenchrus +
species +
membranous +
0.36 cm3.6 mm <br />0.0036 m <br /> (0.54 cm5.4 mm <br />0.0054 m <br />) +
0.22 cm2.2 mm <br />0.0022 m <br /> (0.49 cm4.9 mm <br />0.0049 m <br />) +
acuminate +  and ovate +
acuminate +  and ovate +
aquatic +  and terrestrial +
dioecious +, monoecious +  and synoecious +