Rhynchospora latifolia |
Rhynchospora kunthii |
|
---|---|---|
sandswamp whitetop |
Kunth's beaksedge |
|
Habit | Plants perennial, cespitose or solitary, to 100 cm; rhizomes scaly, 3–4 mm thick. | Plants solitary or in small tufts, (5–)10–70 cm, clonal; rhizomes strongly present, stoloniferous. |
Culms | arching or erect, leafy-based, distally wandlike, terete, multiribbed. |
leafiest toward base, ± trigonous, slender. |
Leaves | ascending to spreading, overtopped by scape; blades linear, proximally flat, 2.5–5 mm wide, apex subulate, trigonous. |
basal leaves spreadingascending, distal more erect, mostly exceeded by culms (except in highaltitude forms); blades proximally flat or strongly folded, 1.5–4 mm wide, apex trigonous, subulate. |
Inflorescences | terminal, headlike clusters of spikelets, clusters dense, leafy-involucrate; involucral bracts several, spreading to downcurved, longest 6–13 cm × 5–10 mm, mostly white to midbract, then green, abruptly narrowly linear. |
spikelet clusters (2–)3–5, compact, proximalmost widely spaced, turbinate to ovoid; peduncles ascending; branches ascending to spreading; leaf bracts exceeding proximalmost clusters, exceeded by distal cluster. |
Spikelets | white, ovoid, 5–7 mm; fertile scales boatshaped, sharply curved-keeled, 5 mm, apex acute. |
deep redbrown to nearly black, ovoid, 3–4 mm, apex acute; fertile scales ovate, 2.5–3 mm, apex acute, midrib included or shortexcurrent. |
Flowers | perianth absent. |
perianth bristles 6, some short, some extending to or nearly to tubercle base, antrorsely barbellate. |
Fruits | several per spikelet, 1.5–2 mm; body yellowish to deep brown, tumidly lenticular, broadly obovoid to orbicular or oblate, 1.5 mm, widest at or toward midbody, margins flowing to tubercle; surfaces with many fine rows of vertical shallow lattices, their contiguous ends making transverse rows of papillae; tubercle crescent-based, depressed-triangular, 0.5 mm, apex acute. |
2–3 per spikelet, 2–2.1 mm; body pale yellowbrown, lenticular, broadly ellipsoidobovoid, 1.3–1.6 × 1–1.2 mm; surfaces transversely irregularly rugulose, intervals with rows of vertical, narrowly rectangular alveolae; tubercle evenly or concavely triangular, 0.5–0.6(–0.7) mm. |
2n | = 12. |
|
Rhynchospora latifolia |
Rhynchospora kunthii |
|
Phenology | Fruiting late spring–summer. | Fruiting late spring–summer. |
Habitat | Sands and peats of bogs in pine savannas and flatwoods | Marsh meadows, seeps, boggy sites |
Elevation | 0–200 m (0–700 ft) | 1000–3500 m (3300–11500 ft) |
Distribution |
AL; FL; GA; LA; MS; NC; SC; TX
|
CA; Mexico; South America (Colombia) |
Discussion | A specimen collected near Tullahoma, Tennessee, reported as Dichromena latifolia (A. Gattinger 1901), was later destroyed by fire. I did not see the specimen, nor was a description of it published. Because extant populations of the similar Rhynchospora colorata are just over the border in Alabama, that species is likely to have been the one found by Gattinger. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 23. | FNA vol. 23, p. 225. |
Parent taxa | Cyperaceae > Rhynchospora | Cyperaceae > Rhynchospora |
Sibling taxa | ||
Synonyms | Dichromena latifolia, R. stellata var. latifolia | R. schaffneri |
Name authority | (Baldwin) W. W. Thomas: Mem. New York Bot. Gard. 37: 86. (1984) | Nees ex Kunth: Enum. Pl. 2: 296. (1837) |
Web links |