Cenchrus echinatus |
Cenchrus tribuloides |
|
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burgrass, common sandbur, field sandbur, konpeito-gusa, sandburr, se mbulabula, southern sandbur, vao tui tui |
dune sandbur, sanddune sandbur |
|
Habit | Plants annual. | Plants annual. |
Culms | 20-100 cm, ascending from a geniculate base. |
10-70 cm, decumbent, branching and rooting at the lower nodes. |
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. |
compressed, glabrous or pubescent; ligules 1-2.1 mm; blades 2-14 cm long, 3-14.2 mm wide. |
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. |
2-8.2 cm; fascicles 9-16 mm long, 4-8 mm wide, imbricate, ovoid, densely pubescent; bristles 15-43; outer bristles usually present, flattened or terete; inner bristles 4-8 mm long, 1.2-3 mm wide, fused for at least 1/2 their length, forming a distinct cupule, the distal portions diverging at irregular intervals from the cupule, stramineous or purple. |
Spikelets | 2-3(4) per fascicle, 4.8-7 mm. |
1(2) per fascicle, 6-8.8 mm. |
Caryopses | ovoid, 1.2-3.2 mm long, 1.3-2.2 mm wide. |
2.6-4 mm long, 2.2-3.1 mm wide, ovoid-elliptic. |
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. |
glumes 1-4 mm; upper glumes 4.9-6.8 mm, 3-7-veined; lower lemmas 5.5-7.5 mm, 3-7-veined, enclosing the palea; upper lemmas 6-8.7 mm; anthers 0.8-2.8 mm. |
2n | = (34), 68. |
= 34. |
Cenchrus echinatus |
Cenchrus tribuloides |
|
Distribution |
AL; AZ; CA; DC; FL; GA; LA; MD; MS; NC; NM; OK; SC; TX; VA; HI; PR; Virgin Islands
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AL; CT; DE; FL; GA; LA; MA; MD; ME; MS; NC; NJ; NY; PA; SC; VA; VT; HI
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Discussion | 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. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Cenchrus tribuloides grows in moist, sandy dunes and is restricted to the eastern United States. It differs from C. spinifex in its larger spikelets and smaller number of spikelets per fascicle, and from C. longispinus in its densely pubescent fascicles, fewer bristles, and wider inner bristles. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 25, p. 531. | FNA vol. 25, p. 534. |
Parent taxa | Poaceae > subfam. Panicoideae > tribe Paniceae > Cenchrus | Poaceae > subfam. Panicoideae > tribe Paniceae > Cenchrus |
Sibling taxa | ||
Synonyms | C. echinatus var. hillebrandianus | |
Name authority | L. | L. |
Web links |