Rhynchospora pusilla |
Rhynchospora caduca |
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anglestem beaksedge |
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Habit | Plants perennial, densely cespitose, 15–50(–60) cm; rhizomes absent. | Plants perennial, cespitose, 70–150 cm; rhizomes often present, short, scaly. |
Culms | erect or arching, leafy toward base, filiform, terete, wiry. |
erect or ascending, leafy, trigonous. |
Leaves | overtopped by culm; blades linear to filiform, channeled, 0.3–0.5 mm wide, margins deeply involute, apex setaceous. |
exceeded by culm; blades linear, proximally 4–7 mm wide, apex trigonous, tapering. |
Inflorescences | spikelet clusters 1–2(–3), dense to open, narrowly to broadly turbinate; branches capillary, variously elongate; leafy bracts setaceous, equaling or exceeding clusters. |
terminal and axillary; clusters 3–6, mostly dense, narrowly to broadly turbinate, branches ascending; leafy bracts exceeeding proximalmost inflorescences. |
Spikelets | variously brown, ellipsoid, 2–3 mm, apex sharply acute; fertile scales ovate to nearly orbiculate, rounded, 1.2–1.8 mm, apiculate, convexcupulate, midrib slender, mostly included. |
rich brown, ovoid, (3–)4–5 mm, apex acuminate; fertile scales ovate, 2.5–3.5 mm, apex acuminate, midrib included or shortexcurrent. |
Flowers | perianth absent. |
perianth bristles mostly 6, exceeding tubercle tip. |
Fruits | 2–3 per spikelet, 0.7–0.9(–1) mm; body pale, obovoid-lenticular, (0.5–)0.6–0.9 × 0.4–0.5 mm, margin wirelike; surfaces transversely rugulose; tubercle buttonlike, depressed triangular, 0.05–0.1 mm, base lunate atop rounded fruit body. |
mostly 3–4 per spikelet, 2–2.2 mm; body brown on short pedicellar (to 0.3 mm) stalk, broadly obovoid, lenticular, 1.3–1.5 × 1–1.5 mm, surfaces transversely rugulose, vertically finely striate and rectangularalveolate; tubercle compressed, triangular acuminate, 0.5–0.8 mm, edges setulose. |
Rhynchospora pusilla |
Rhynchospora caduca |
|
Phenology | Fruiting summer–fall. | Fruiting summer–fall. |
Habitat | Moist sands, peats and silts of low meadows, savannas, bogs, seeps, pond shores | Low meadows, clearings, marshes, marsh borders, seeps, bog moats, savannas, ditches, pine flatwoods, swamps |
Elevation | 0–300 m (0–1000 ft) | 0–400 m (0–1300 ft) |
Distribution |
AL; FL; GA; LA; MS; NC; SC; TX; Mexico; Central America; West Indies |
AL; AR; FL; GA; LA; MS; NC; OK; SC; TN; TX; VA
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Discussion | Rhynchospora caduca has its closest relationships with the even more robust R. odorata Grisebach, on the one hand, and the swampinhabiting, more slender, and rhizomatous R. mixta Britton ex Small, on the other. Intergrades with R. odorata appear in Alabama and northwest Florida; intergrades with R. mixta appear where ranges overlap in both the Atlantic and Gulf coastal plains. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 23, p. 220. | FNA vol. 23, p. 223. |
Parent taxa | Cyperaceae > Rhynchospora | Cyperaceae > Rhynchospora |
Sibling taxa | ||
Synonyms | Phaeocephalum pusillum, R. intermixta | Phaeocephalum caducum, R. patula |
Name authority | Chapman ex M. A. Curtis: Amer. J. Sci. Arts, ser. 2, 7: 409. (1849) | Elliott: Sketch Bot. S. Carolina 1: 62. (1816) |
Web links |