Rhynchospora wrightiana |
Rhynchospora debilis |
|
---|---|---|
Wright's beaksedge |
savannah beaksedge |
|
Habit | Plants perennial, cespitose, 10–50 cm; rhizomes absent. | Plants perennial, cespitose, 20–45 cm; rhizomes absent. |
Culms | slender, ± filiform, leafy, terete to bluntly trigonous. |
erect to arching or spreading, leafy, ± filiform, ± terete, stiff to rather lax. |
Leaves | shorter than culm; blades spreading to ascending, ± filiform, proximally flat, 0.5–1(–1.5) mm, apex tapering, trigonous. |
exceeded by culm; blades linearfiliform, proximally shallowly concave, 1 mm, apex tapering, trigonous, blunt or broadly acute. |
Inflorescences | spikelet clusters 1–3, loose to dense, widely spaced to close together, turbinate to hemispheric; leafy bracts setaceous, mostly exceeding spikelet clusters. |
spikelet clusters 1–2, mostly compact, turbinate to hemispheric; leafy bracts setaceous, exceeding spikelet clusters. |
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 redbrown, ovoid, 2–3 mm, apex acute; fertile scales obovate, 1.5–1.7(–2) mm, apex broadly rounded or retuse, midrib excurrent as cusp or mucro to 0.5 mm. |
Flowers | bristles 6, of various length, mostly extending from fruit midbody to tubercle base, antrorsely barbellate. |
bristles 6 or vestigial, rarely reaching fruit midbody, antrorsely 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. |
1–2 per spikelet,1.7–2 mm; body brown with large pale center, lenticular, broadly obovoid to ± orbicular, 1.2–1.5 × 1.4–1.6 mm; tubercle flat, triangular, concave-sided, 0.4–0.6 mm, sometimes apiculate. |
Rhynchospora wrightiana |
Rhynchospora debilis |
|
Phenology | Fruiting late spring–fall or all year (south). | Fruiting late spring–fall. |
Habitat | Sands and peats in flatwoods, pine savannas, pond and stream banks, bogs, and seeps | Sands and peats in low, open fields, bogs, seeps, low pinelands, savannas, and ditch banks |
Elevation | 0–200 m (0–700 ft) | 0–200 m (0–700 ft) |
Distribution |
AL; FL; GA; MS; NC; SC; VA; Central America; West Indies
|
AL; FL; GA; LA; MS; NC; SC; TX; VA |
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.) |
Rhynchospora debilis is very similar to R. wrightiana except it has smaller spikelet clusters and more depressed fruit tubercles. It is a common invader of cutover and bulldozed low pineland where it assumes a lowspreading habit, its many culms radiating from the common center much like spokes in a wheel. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 236. | FNA vol. 23. |
Parent taxa | Cyperaceae > Rhynchospora | Cyperaceae > Rhynchospora |
Sibling taxa | ||
Synonyms | R. gracillima, R. distans var. gracillima, R. distans var. tenuis | R. fascicularis var. debilis |
Name authority | Boeckeler: Flora 64: 78. (1881) | Gale: Rhodora 46: 194, plate 826, figs. 5A, B. (1944) |
Web links |