Rhynchospora latifolia |
Rhynchospora stenophylla |
|
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sandswamp whitetop |
coastal plain beaksedge |
|
Habit | Plants perennial, cespitose or solitary, to 100 cm; rhizomes scaly, 3–4 mm thick. | Plants perennial, densely cespitose, 30–60(–90) cm; rhizomes forking, compact. |
Culms | arching or erect, leafy-based, distally wandlike, terete, multiribbed. |
lax, leafy toward base, filiform, ± terete. |
Leaves | ascending to spreading, overtopped by scape; blades linear, proximally flat, 2.5–5 mm wide, apex subulate, trigonous. |
ascending, exceeded by culm; blades filiform, to 0.5 mm, margins mostly involute, apex trigonous, tapering. |
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. |
mostly lax cymes or clusters of cymes, 1–2, sparse, turbinate, branches capillary; leafy bracts setaceous, exceeding proximal cymes, shorter than, equaling or slightly exceeding distal cymes. |
Spikelets | white, ovoid, 5–7 mm; fertile scales boatshaped, sharply curved-keeled, 5 mm, apex acute. |
redbrown, fusiformlanceoloid, 5 mm, apex acute; fertile scales lanceolate, 3.5–4.5 mm, apex acute or acuminate, midrib included or shortexcurrent. |
Flowers | perianth absent. |
perianth bristles 6, exceeding tubercle base, antrorsely barbellate, basally setose. |
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. |
1 per spikelet, 2.8–3 mm; body pale brown, obovoidpyriform, tumidly lenticular, 1.5–1 × 1 mm; surfaces transversely wavyrugose, intervals vertically striate with narrow, raised alveolae; tubercle flat, narrowly triangular-subulate, (0.8–)1–1.5 mm. |
2n | = 12. |
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Rhynchospora latifolia |
Rhynchospora stenophylla |
|
Phenology | Fruiting late spring–summer. | Fruiting spring–summer. |
Habitat | Sands and peats of bogs in pine savannas and flatwoods | Sands and peats of bogs, seeps, pond shores, flatwoods, and savannas |
Elevation | 0–200 m (0–700 ft) | 0–200 m (0–700 ft) |
Distribution |
AL; FL; GA; LA; MS; NC; SC; TX
|
AL; FL; GA; LA; MS; NC; SC; TX |
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.) |
Rhynchospora stenophylla may occasionally be confused with the closely related R. rariflora but can be distinguished by its taller and wispier habit, its longer spikelets of narrower outline, and the distinctly longer fruit tubercle. Both species are usually found on wet substrates; R. stenophylla typically is found in the deepest bogs and sphagnous seeps. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23. | FNA vol. 23, p. 221. |
Parent taxa | Cyperaceae > Rhynchospora | Cyperaceae > Rhynchospora |
Sibling taxa | ||
Synonyms | Dichromena latifolia, R. stellata var. latifolia | |
Name authority | (Baldwin) W. W. Thomas: Mem. New York Bot. Gard. 37: 86. (1984) | Chapman: Fl. South. U.S., 525. (1860) |
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