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.
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.
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