Cenchrus spinifex |
|
---|---|
coastal sandbur, common sandbur |
|
Habit | Plants annual or perennial but short-lived; tufted. |
Culms | 30-100 cm, geniculate. |
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. |
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. |
Spikelets | 2-4 per fascicle, 3.5-5.9 mm, glabrous. |
Caryopses | about 2.5 mm long, 1-2 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. |
2n | = 34 (32). |
Cenchrus spinifex |
|
Distribution |
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
|
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.) |
Source | FNA vol. 25, p. 533. |
Parent taxa | Poaceae > subfam. Panicoideae > tribe Paniceae > Cenchrus |
Sibling taxa | |
Synonyms | C. pauciflorus, C. incertus, C. bambusoides |
Name authority | Cav. |
Web links |