Cenchrus echinatus

L.
Common names: Southern sandbur
Synonyms: Cenchrus echinatus var. hillebrandianus
Treatment appears in FNA Volume 25. Treatment on page 531.

Plants annual. Culms 20-100 cm, ascending from a geniculate base. Sheaths from shorter than to equaling the internodes, compressed; ligules 0.7-1.7 mm; blades 4-18 (35) cm long, 2-10 (14.2) mm wide, adaxial surfaces sparsely pilose, hairs papillose-based. Panicles 2.5-12 cm; rachis internodes 2-4 mm; fascicles 5-10 mm long, 3.5-6 (6.3) mm wide, imbricate; outer bristles 10-20, terete, the majority no more than 1/2 as long as the inner bristles; inner bristles 2-5 mm long, 0.6-1.5 mm wide, flattened, not grooved, mostly erect, fused for at least 1/2 their length into a globose cupule, sometimes interlocking at maturity, shortly pubescent, often purple at maturity. Spikelets 2-3 (4) per fascicle, 4.8-7 mm. Lower glumes 1.3-3.4 mm; upper glumes 3.8-5.7 mm, 3-7-veined; lower lemmas 4.5-6.5 mm; upper florets 4.7-7 mm; anthers 0.8-2.4 mm. Caryopses ovoid, 1.2-3.2 mm long, 1.3-2.2 mm wide. 2n = (34), 68.

Distribution

Md., D.C., Miss., Puerto Rico, Okla., Tex., La., Virgin Islands, Calif., Ala., N.C., S.C., Va., Pacific Islands (Hawaii), Ga., Ariz., Fla., N.Mex.

Discussion

Cenchrus echinatus grows in disturbed areas throughout the coastal plain and piedmont of the southern United States, Mexico, Central and South America, and, as an unwelcome introduction, elsewhere.

Selected References

None.

Lower Taxa

None.

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

... more about "Cenchrus echinatus"
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.24 cm2.4 mm <br />0.0024 m <br />) +
anatomy +  and kranz +
Michael T. Stieber +  and J.K. Wipff +
1 (?) +  and 3 (?) +
keeled +  and rounded +
pseudopetiolate +  and branching +
divergent +  and parallel +
intravaginal +, extravaginal +, branching +  and basal +
geniculate +
swelling +
membranous +
disarticulating +  and pseudopetiolate +
non-radiate +  and radiate +
4 cm40 mm <br />0.04 m <br /> (18 cm180 mm <br />0.18 m <br />) +
folded +  and flat +
2mm;10mm +
spikelike +
reduced +
scabridulous +
not developed +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.32 cm3.2 mm <br />0.0032 m <br />) +
0.13 cm1.3 mm <br />0.0013 m <br /> (0.22 cm2.2 mm <br />0.0022 m <br />) +
Southern sandbur +
branched +  and solid +
geniculate +
20 cm200 mm <br />0.2 m <br /> (100 cm1,000 mm <br />1 m <br />) +
Md. +, D.C. +, Miss. +, Puerto Rico +, Okla. +, Tex. +, La. +, Virgin Islands +, Calif. +, Ala. +, N.C. +, S.C. +, Va. +, Pacific Islands (Hawaii) +, Ga. +, Ariz. +, Fla. +  and N.Mex. +
capillary +
germination +
pistillate +  and staminate +
sometimes longer +
compressed +  and terete +
shorter or longer +
subtending +
unequal +
membranous +
papillose-based +
uncinate +
bracteate +  and ebracteate +
1/2 +, 2mm +  and 5mm +
0.6mm +  and 1.5mm +
solid +  and hollow +
cauline +  and basal +
coriaceous +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.17 cm1.7 mm <br />0.0017 m <br />) +
membranous +
inconspicuous +
acute +  and acuminate +
0.13 cm1.3 mm <br />0.0013 m <br /> (0.34 cm3.4 mm <br />0.0034 m <br />) +
0.45 cm4.5 mm <br />0.0045 m <br /> (0.65 cm6.5 mm <br />0.0065 m <br />) +
purplish +  and tawny +
scabridulous +
complex +  and simple +
concealed +  and prominent +
2 +  and 1 +
subterranean +
2.5 cm25 mm <br />0.025 m <br /> (12 cm120 mm <br />0.12 m <br />) +
dry +  and fleshy +
imbricate +  and fascicles +
0.5 cm5 mm <br />0.005 m <br /> (1 cm10 mm <br />0.01 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
3.5mm +  and 6mm +
compressed +
in triplets +  and paired +
unisexual +  and bisexual +
compressed +  and terete +
0.48 cm4.8 mm <br />0.0048 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
1 (?) +  and 3 (?) +
fused +  and free +
2 (?) +  and 3 (?) +
dome--shaped +  and triangular +
Cenchrus echinatus var. hillebrandianus +
Cenchrus echinatus +
Cenchrus +
species +
membranous +
0.47 cm4.7 mm <br />0.0047 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
0.38 cm3.8 mm <br />0.0038 m <br /> (0.57 cm5.7 mm <br />0.0057 m <br />) +
acuminate +  and ovate +
acuminate +  and ovate +
aquatic +  and terrestrial +
dioecious +, monoecious +  and synoecious +