Rhynchospora mixta |
Rhynchospora colorata |
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mingled beaksedge |
starrush whitetop, white star sedge |
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Habit | Plants perennial, cespitose, 80–100 cm; rhizomes stoloniferous, often elongate, slender, to 1 dm or more. | Plants perennial, cespitose or solitary, to 70 cm; rhizomes slender, scaly, to 2 mm thick. |
Culms | erect, slender, leafy-based, trigonous, several-ribbed. |
|
Leaves | exceeded by culm; blades lax, linear, proximally flat, 3–5 mm wide, apex abruptly narrowed, trigonous, subulate. |
spreading to erect, overtopped by culm; blades narrowly linear, proximally flattened, 0.5–3 mm wide, apex tapering, trigonous. |
Inflorescences | spikelet clusters 4–6, mostly widely spaced; peduncles erect or ascending, slender; branches capillary, divaricate, or widely spreading, to small clusters of 1–few spikelets; leafy bracts mostly exceeding clusters. |
terminal, solitary, headlike, dense, white, leafy-involucrate; involucral bracts several, flaring to recurved, white from broadened base nearly to median, then green to tapered tip, longer bracts 13 cm × 2–7 mm. |
Spikelets | lanceovoid, 3–4(–6) mm, apex acute to acuminate; fertile scales elliptic, 2.5 mm, apex acute, midrib forming mucro or awn. |
white, ovoid, 5–7 mm, apex acute; fertile scales many, boatshaped, sharply curvedkeeled, 3–4(–5) mm, apex acute or blunt. |
Flowers | perianth bristles 6, overtopping tubercle, antrorsely barbellate. |
perianth absent. |
Fruits | mostly 2–4(–several) per spikelet, (1.5–)1.8–2(–2.1); body greenish or pale brown, broadly ellipsoid to narrowly obovoid, lenticular, 1.2–1.5 × 1–1.2 mm; surfaces transversely finely wavy-rugulose, intervals vertically striatealveolate, or alveolae isodiametric; tubercle flat, triangular-subulate, 0.5–0.6(–0.8) mm. |
several per spikelet, 1.5–1.7(–2) mm; body yellow to mahogany, broadly pyriformobovoid, tumidly lenticular, 1 × 0.5–0.7 mm, widest at apex, margins thickened, interrupted at base of tubercle; surfaces transversely undulaterugose, ridges contiguous, of shortlinear papillae; tubercle broadly triangular, 0.5–0.6 mm, graycrustaceous, apex short acuminate. |
2n | = 12. |
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Rhynchospora mixta |
Rhynchospora colorata |
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Phenology | Fruiting summer–fall. | Fruiting late spring–summer. |
Habitat | Sandy silts of swamp forests and environs | Sands, peats, and silt of interdunal swales, shores, meadowy swales, and marsh edges, sometimes fens, usually on circumneutral or basic substrates |
Elevation | 0–200 m (0–700 ft) | 0–300 m (0–1000 ft) |
Distribution |
AL; FL; GA; LA; MS; NC; SC; TX
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AL; AR; FL; GA; LA; MS; NC; SC; TX; VA; Mexico; Central America; West Indies; South America (French Guiana)
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Discussion | Some extremes of Rhynchospora caduca with more diffuse inflorescences are mistaken for R. mixta, particularly those in which ultimate inflorescence branches lead to solitary spikelets. In those rare instances one should find a somewhat larger spikelet and a broader fruit than is typical for R. mixta. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Rhynchospora colorata is a slender and clonal version of R. latifolia, with a distinct preference for more basic substrates; involucral bracts are very slender and have a longer portion of green, usually reaching well proximal to midbract. See also 16. Rhynchospora latifolia. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 224. | FNA vol. 23, p. 215. |
Parent taxa | Cyperaceae > Rhynchospora | Cyperaceae > Rhynchospora |
Sibling taxa | ||
Synonyms | Phaeocephalum proliferum, R. prolifera | Schoenus coloratus, Dichromena cephalotes, Dichromena colorata, Dichromena leucocephala, R. drummondiana, Scirpus cephalotes |
Name authority | Britton: in J. K. Small, Fl. S.E. U.S., 197, 1328. (1903) | (Linnaeus) H. Pfeiffer: Repert. Spec. Nov. Regni Veg. 38: 89. (1935) |
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