Rhynchospora caduca |
Rhynchospora breviseta |
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anglestem beaksedge |
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Habit | Plants perennial, cespitose, 70–150 cm; rhizomes often present, short, scaly. | Plants perennial, densely cespitose, knottybased, 20–40 cm; rhizomes absent. |
Culms | erect or ascending, leafy, trigonous. |
leafy at base, filiform, wiry. |
Leaves | exceeded by culm; blades linear, proximally 4–7 mm wide, apex trigonous, tapering. |
blades filiform, nearly reaching inflorescence tip or much shorter, to 0.3 mm thick, apex tapering. |
Inflorescences | terminal and axillary; clusters 3–6, mostly dense, narrowly to broadly turbinate, branches ascending; leafy bracts exceeeding proximalmost inflorescences. |
spikelet clusters mostly 2–6, simple or reduced to 1 spikelet, often with 2 capillary branches, one divaricate or reflexed, 1 ascending; leafy bracts single per cluster, filiform, setaceous, with clusters appearing lateral to bracts. |
Spikelets | rich brown, ovoid, (3–)4–5 mm, apex acuminate; fertile scales ovate, 2.5–3.5 mm, apex acuminate, midrib included or shortexcurrent. |
pale redbrown, ellipsoidlanceoloid, 5–6(–8) mm, apex acute to acuminate; fertile scales narrowly ovate, 3–5(–6) mm, apex acute, midrib included or shortexcurrent. |
Flowers | perianth bristles mostly 6, exceeding tubercle tip. |
perianth bristles 6, not reaching past fruit midbody, stubby, plumose to near tip. |
Fruits | 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. |
3–8 per spikelet, 2–2.5 mm; body light brown to brown, ellipsoid-obovoid, tumidly lenticular, 1.5–2 × 1.6–1.7 mm; surfaces faintly, interruptedly crossrugulose, apically indented under tubercle; tubercle lowconic, 0.5 mm, base flaring, circular. |
Rhynchospora caduca |
Rhynchospora breviseta |
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Phenology | Fruiting summer–fall. | Fruiting spring–summer. |
Habitat | Low meadows, clearings, marshes, marsh borders, seeps, bog moats, savannas, ditches, pine flatwoods, swamps | Moist to wet sands or peats of bogs, depressions in savannas, open pinelands, pond shores |
Elevation | 0–400 m (0–1300 ft) | 0–200 m (0–700 ft) |
Distribution |
AL; AR; FL; GA; LA; MS; NC; OK; SC; TN; TX; VA
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AL; FL; GA; LA; MS; NC; SC; VA; West Indies |
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.) |
Rhynchospora breviseta is sympatric with R. oligantha over much of its range; intergrades have not been seen. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 223. | FNA vol. 23. |
Parent taxa | Cyperaceae > Rhynchospora | Cyperaceae > Rhynchospora |
Sibling taxa | ||
Synonyms | Phaeocephalum caducum, R. patula | R. oligantha var. breviseta |
Name authority | Elliott: Sketch Bot. S. Carolina 1: 62. (1816) | (Gale) Channell: Rhodora 58: 336. (1956) |
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