The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

coastal sandbur, common sandbur

burgrass, cenchrus à épines longues, field sandbur, long-spine sandbur, mat sandbur, sandbur

Habit Plants annual or perennial but short-lived; tufted. Plants annual; tufted.
Culms

30-100 cm, geniculate.

20-90 cm, sometimes decumbent, often with many branches arising from the base.

Sheaths

compressed, glabrous or sparsely pilose;

ligules 0.5-1.4 mm;

blades 3-28 cm long, (1)3-7.2 mm wide, glabrous or sparsely long-pilose adaxially.

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

3-5(8.5) cm;

fascicles 5.5-10.2 mm long, 2.5-5 mm wide, imbricate, ovoid to globose, glabrous or sparesely to moderately pubescent;

outer bristles, when present, mostly flattened;

inner bristles 8-40 (rarely more), 2-5.8 mm long, 1-2 mm wide, fused at least 1/2 their length, forming a distinct cupule, the distal portions usually diverging from the cupule at multiple, irregular intervals, sometimes diverging at more or less the same level, ciliate at the base, pubescent, stramineous to mauve or purple, flattened.

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

2-4 per fascicle, 3.5-5.9 mm, glabrous.

2-3(4) per fascicle, (4)5.8-7.8 mm.

Caryopses

about 2.5 mm long, 1-2 mm wide, ovoid.

2-3.8 mm long, 1.5-2.6 mm wide, ovoid.

Lower

glumes 1-3.3 mm;

upper glumes (2.8)3.5-5 mm, 5-7-veined;

lower florets sometimes staminate;

lower lemmas 3-5(5.9) mm, 5-7-veined;

lower paleas sometimes reduced or absent;

anthers 1.3-1.6 mm;

upper lemmas 3.5-5(5.8) mm;

anthers 0.5-1.2 mm.

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.

2n

= 34 (32).

= 34 (38).

Cenchrus spinifex

Cenchrus longispinus

Distribution
from FNA
AL; AR; AZ; CA; DC; FL; GA; KS; KY; LA; MA; MD; ME; MS; NC; NM; NV; OK; SC; TN; TX; VA; VT; PR; Virgin Islands
[WildflowerSearch map]
from FNA
AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; BC; ON; QC
[WildflowerSearch map]
[BONAP county map]
Discussion

Cenchrus spinifex is common in sandy woods, fields, and waste places throughout the southern United States and southwards into South America. It may be more widespread than shown in the northern portion of the contiguous United States because it has often been confused with C. tribuloides. Cenchrus spinifex differs from C. tribuloides in its glabrous or less densely pubescent fascicles, narrower inner bristles, and larger number of bristles. It has also been confused with C. longispinus but differs in having shorter spikelets, fewer bristles overall, wider inner bristles, and outer bristles that are usually flattened rather than usually terete.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

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.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 25, p. 533. FNA vol. 25, p. 534.
Parent taxa Poaceae > subfam. Panicoideae > tribe Paniceae > Cenchrus Poaceae > subfam. Panicoideae > tribe Paniceae > Cenchrus
Sibling taxa
C. biflorus, C. brownii, C. echinatus, C. gracillimus, C. longispinus, C. myosuroides, C. tribuloides
C. biflorus, C. brownii, C. echinatus, C. gracillimus, C. myosuroides, C. spinifex, C. tribuloides
Synonyms C. pauciflorus, C. incertus, C. bambusoides C. carolinianus
Name authority Cav. (Hack.) Fernald
Web links