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.
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.
Common Name: southern sandbur
Duration: Annual
Nativity: Native
Lifeform: Graminoid
General: Annual with stems 20-100 cm, ascending from a geniculate base; sheaths shorter than or equaling the internodes, compressed.
Vegetative: Blades 4-18 cm long, 2-10 mm wide, upper surfaces sparsely pilose, hairs papillose based, ligules 0.5-1.5 mm.
Inflorescence: Panicles 2.5-12 cm, with internodes on the rachis of 2-4 mm, fascicles 5-10 mm long, 3.5-6 mm wide, imbricate; outer bristles 10-20, terete, the majority half as long as inner bristles; inner bristles 2-5 mm long, 0.5-1.5 mm wide, flattened, not grooved, mostly erect, fused for half the length into a globose cupule, sometimes interlocking at maturity, shortly pubescent, often purple at maturity; 2-3 spikelets per fascicle, 4.5-7 mm long, disarticulation at base of fascicles; ovate lower glumes 1-3.5 mm, ovate upper glumes 3.5-6 mm, 3-7 veined, lower lemmas 4.5-6.5 mm, upper florets 4.5-7 mm, bisexual.
Ecology: Found on disturbed sites, along fields and roads; flowers in summer.
Notes: Differs from the similar C. spinifex by its having larger spikelets and burs that are mostly broader than longer, mostly four flowered. You-ll know this plant if you step on it in bare feet.
Ethnobotany: Unknown
Etymology: Cenchrus is thought to be from Greek kenchros, millet, while echinatus means covered in prickles like a hedgehog.
Synonyms: Cenchrus echinatus var. hillebrandianus
Editor: SBuckley, 2010
Annual, ascending from a geniculate base, 2-8 dm; lvs 4-25 cm נ4-10 mm; burs well spaced on a flexuous rachis, short-hairy, 5-10 נ3.5-6 mm, truncate at the base, the single row of coarse upper spines 2-5 mm, retrorsely scabrid, mostly erect, sometimes interlocking, those of the outer rows finer, half as long, more divergent or some of them reflexed; spikelets 2-3 per bur, 5-7.5 mm; 2n=34, 68. Sandy waste places and forest-margins; trop. Amer., n. to N.C. and even D.C.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
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