Plants annual; tufted. Culms 20-90 cm, sometimes decumbent, often with many branches arising from the base. Sheaths strongly compressed-keeled; ligules 0.6-1.8 mm; blades 4-27 cm long, 1.5-5(7.5) mm wide, adaxial surfaces scabrous or sparsely pilose. Panicles 1.5-8(10) cm; fascicles 8.3-11.9 mm long, 3.5-6 mm wide, somewhat globose, medium- to short-pubescent; bristles 45-75; outer bristles numerous, shorter and thinner than the inner bristles, imbricate, mostly terete, reflexed; inner bristles 3.5-7 mm long, 0.5-0.9(1.4) mm wide at the base, irregularly placed, fused for 1/2 their length or more, forming a distinct cupule, the distal portions diverging at irregular intervals from the cupule, often grooved along the margins, purple-tinged. Spikelets 2-3(4) per fascicle, (4)5.8-7.8 mm. Lower glumes 0.8-3 mm; upper glumes 4-6 mm, 3-5-veined; lower florets often staminate; lower lemmas 4-6.5 mm, 3-7-veined; anthers 1.5-2 mm; upper lemmas 4-7(7.6) mm; anthers 0.7-1 mm, seemingly not well-developed at anthesis. Caryopses 2-3.8 mm long, 1.5-2.6 mm wide, ovoid. 2n = 34 (38).

Cenchrus longispinus grows in sandy woods, fields, and waste ground in southern Canada and the contiguous United States. Its range extends southwards to Venezuela. It is often confused with C. spinifex and C. tribuloides; see discussion under those species.

Annual herb, tufted 20 cm - 1 m tall Leaves: alternate, two-ranked. Sheaths strongly compressed and keeled, hairy towards the apex. Ligules 0.5 - 2 mm long. Blades 4 - 27 cm long, 1.5 - 7 cm wide, linear, flat, parallel-veined, rough or sparsely soft-hairy on top. Inflorescence: a terminal, spike-like, branched arrangement of "burs" (termed fascicles), 1.5 - 10 cm long. Fruit: a caryopsis, indehiscent, enclosed within the persistent lemma and palea, 2 - 4 mm long, 1.5 - 2.5 mm wide, egg-shaped. Culm: spreading or ascending, many-branched from base, 20 cm - 1 m long, round in cross-section, solid, knee-like, internodes hollow. Spikelets: two to four per fascicle, stalkless, 5 - 8 mm long, oblong lance-shaped. Florets: two per spikelet. Lower floret often male. Upper floret bisexual. Anthers three, 1.5 - 2 mm long (lower) or 0.5 - 1 mm long (upper). Stigmas red. Fascicles: (the "burs" of the inflorescence) composed of many stiff, partially fused spines, stalkless, 8 - 12 mm long, 3.5 - 6 mm wide, somewhat spherical, hairy, enclosing spikelets. Glumes:: Lower glumes 0.5 - 3 mm long, egg-shaped with a more or less pointed apex, one-veined. Upper glumes 4 - 6 mm long, egg-shaped, three- to five-veined. Lemmas:: Lower lemmas 4 - 6.5 mm long, equaling their paleas, egg-shaped, three- to seven-veined. Upper lemmas 4 - 7 mm long, nearly equaling their paleas, egg-shaped with a tapering apex, obscurely veined. Paleas:: Lower paleas purplish or tawny. Upper paleas egg-shaped with a tapering apex, obscurely veined.

Similar species: No information at this time.

Flowering: July to mid-September

Habitat and ecology: Common in sandy soil.

Occurence in the Chicago region: native

Notes: The "burs" of this species often adhere to shoe laces and clothing.

Etymology: Cenchrus comes from cenchros, a modified Greek name for Setaria italica (millet). Longispinus means long-spined.

Author: The Morton Arboretum

FNA 2003, Gould 1980

Common Name: mat sandbur Duration: Annual Nativity: Native Lifeform: Graminoid General: Loosely tufted, often prostrate and mat forming annuals; stems 10-40 cm long, branched at the base, sometimes rooting at the nodes, geniculate, glabrous, leafy.  Vegetative: Sheaths compressed-keeled, the collar sometimes puberulent, otherwise glabrous, margins scarious, sometimes extended as membranous auricles, sometimes diverging from the stem; ligule a dense fringe of hairs, 0.5-1.5 mm long, marginal hairs sometimes up to Inflorescence: Panicle 3-6 cm long, bearing 4-12 burs, rachis geniculate, flattened and angled, scabrous to glabrous; bur urceolate to globose, the body 3-5 mm broad when pressed, enclosing 2 sessile spikelets and covered with 45-55 spines, upper spines large, flat, spreading to ascending. Ecology: Found in open ground and waste places, a weedy plant in disturbed areas, often in sandy soil. Notes: This plant has terrifically gnarly seeds. Distinguished from C. spinifex by having longer spikelets, more brisles, narrower inner bristles, and terete outer bristles. Ethnobotany: Unknown Etymology: Cenchrus is thought to be from Greek kenchros, millet, and longispinus means long spines. Synonyms: Cenchrus carolinianus Editor: SBuckley, 2010

Spreading or ascending annual 2-8 dm, usually branched; sheaths villous-ciliate distally; blades 6-18 cm נ3-7 mm; burs hairy, 8-12 נ3.5-6 mm (spines excluded), with numerous (mostly 45-75) retrorsely barbed, slender spines 3.5-7 mm, the lower spines relatively short and pointed downward; spikelets 2-3(4) per bur, 6-8 mm, exserted at the tip, visible down to the middle through the lateral cleft in the bur; 2n=34. A weed in sandy soil or disturbed habitats; Me. to Fla., w. to N.D., Oreg., Calif. and Tex.

Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

©The New York Botanical Garden. All rights reserved. Used by permission.

From Flora of Indiana (1940) by Charles C. Deam

This sandbur prefers dry, sandy to very sandy soil and is found throughout the state where its habitat occurs. It is local where its habitat is absent and is frequent to common in the northern part of the state in the sandy areas, where it is a very obnoxious weed. It is found in cultivated grounds and waste places, in sandy railroad ballast, and along roadsides. 

......

Deam (1929): The spines of this species [called C. pauciflorus by Deam] are so sharp and stout that they easily penetrate the flesh of man and animals. The "burs" are dangerous sto grazing animals and annoying to man by adhering to his clothing. In the sandy soils of our northern counties it is a nuisance in orchards and truck patches where the workman must be constantly on guard to avoid being injured by the sharp spines.

No doubt this grass has been introduced into Indiana. It is now common in Steuben County but Bradner, who published a flora of the county in 1892, did not list it. Van Gorder, who published a flora of Noble County in 1894, says: "... a few specimens, probably introduced." Dr. Clapp, who made a list of the plants in the vicinity of New Albany from 1836 until 1862, did not list it, but McMurtie listed it for Louisville in 1819.