Rhynchospora wrightiana |
Rhynchospora knieskernii |
|
---|---|---|
Wright's beaksedge |
knieskern's beaksedge |
|
Habit | Plants perennial, cespitose, 10–50 cm; rhizomes absent. | Plants perennial, cespitose, to 50 cm; rhizomes absent. |
Culms | slender, ± filiform, leafy, terete to bluntly trigonous. |
erect to arching, leafy, linear to filiform, nearly triangular. |
Leaves | shorter than culm; blades spreading to ascending, ± filiform, proximally flat, 0.5–1(–1.5) mm, apex tapering, trigonous. |
ascending, overtopped by culm; blades flat, linear to filiform, to 1.8 mm wide, apex distally involute, trigonous, setaceous. |
Inflorescences | spikelet clusters 1–3, loose to dense, widely spaced to close together, turbinate to hemispheric; leafy bracts setaceous, mostly exceeding spikelet clusters. |
terminal and axillary, spikelet clusters 2–4, widely spaced, the lowest near plant base; clusters compact, broadly turbinate to hemispheric, to 1.5 cm wide; leafy bracts curved, setaceous, slightly to greatly overtopping subtended compounds. |
Spikelets | dark redbrown, lanceovoid, 2.5–3.5(–4) mm, apex acute; fertile scales ovate, 2–3.5 mm, apex acute or acuminate, rarely minutely awned. |
dark brown, lance-ellipsoid, 2–3 mm; fertile scales 2 mm, apex acute, midrib short-excurrent or not. |
Flowers | bristles 6, of various length, mostly extending from fruit midbody to tubercle base, antrorsely barbellate. |
perianth bristles 6, ± as long as fruit body, retrorsely barbellate. |
Fruits | 1–2 per spikelet, (2–)2–2.5 mm; body brown with pale center, lenticular, broadly ellipsoid, 1.5–1.7 × 1.2–1.3 mm, surfaces nearly smooth or very finely cancellate; tubercle flat, triangular with short-oblong, blunttipped nose, or triangularsubulate, 0.5–0.8 mm. |
mostly 2 per spikelet, 1.5–1.9 mm; body brown with yellowish center, ellipsoid, lenticular distal to short stipe, 1–1.3 × 0.6–0.8 mm; tubercle triangular, 0.3–0.6 mm, distinctly shorter than fruit body. |
Rhynchospora wrightiana |
Rhynchospora knieskernii |
|
Phenology | Fruiting late spring–fall or all year (south). | Fruiting summer–fall. |
Habitat | Sands and peats in flatwoods, pine savannas, pond and stream banks, bogs, and seeps | Moist to wet pine barrens, sand pits, borrow pits |
Elevation | 0–200 m (0–700 ft) | 0–100 m (0–300 ft) |
Distribution |
AL; FL; GA; MS; NC; SC; VA; Central America; West Indies
|
DE; NJ |
Discussion | The morphologic boundary between Rhynchospora wrightiana and R. fascicularis (particularly morphs of R. fascicularis referred to R. fascicularis var. distans) is difficult, as recent annotations of the material testify. It is best to consider R. wrightiana as a lower, distinctly filiformleaved entity with darker brown, shorter spikelets and shorter fruit. Kükenthal’s concept of R. wrightiana appears to include a considerable amount of R. fascicularis var. distans. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. Rhynchospora knieskernii is in the Center for Plant Conservation’s National Collection of Endangered Plants. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 236. | FNA vol. 23, p. 211. |
Parent taxa | Cyperaceae > Rhynchospora | Cyperaceae > Rhynchospora |
Sibling taxa | ||
Synonyms | R. gracillima, R. distans var. gracillima, R. distans var. tenuis | |
Name authority | Boeckeler: Flora 64: 78. (1881) | J. Carey: Amer. J. Sci. Arts, ser. 2, 4: 25. (1847) |
Web links |