Rhynchospora latifolia |
Rhynchospora ciliaris |
|
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sandswamp whitetop |
fringe beaksedge |
|
Habit | Plants perennial, cespitose or solitary, to 100 cm; rhizomes scaly, 3–4 mm thick. | Plants perennial, cespitose, 30–90 cm; rhizomes absent. |
Culms | arching or erect, leafy-based, distally wandlike, terete, multiribbed. |
erect or ascending, terete to obscurely trigonous, multiribbed, densely leafybased, slender, stiff, papillose to scabridpuberulent. |
Leaves | ascending to spreading, overtopped by scape; blades linear, proximally flat, 2.5–5 mm wide, apex subulate, trigonous. |
forming strong rosette, distal widely spaced, much exceeded by scape; basal leaf blades shortlinear, flat, 4–6 mm wide, culm leaf blades narrower, longer, all ciliate, apex bluntly acute. |
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. |
terminal; spikelet cluster 1, crowded, hemispheric, often lobed, to 2 cm wide; bracts strongly ciliate distally; longer leafy bracts exceeding cluster. |
Spikelets | white, ovoid, 5–7 mm; fertile scales boatshaped, sharply curved-keeled, 5 mm, apex acute. |
dark redbrown, ovoid, 4–5(–6) mm, apex acute; fertile scales broadly ovate, 4–4.5 mm, apex blunt, sometimes apiculate or with mucro to 1 mm, midrib scabrid. |
Flowers | perianth absent. |
bristles 6, some vestigial, none reaching past fruit midbody, 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. |
1–2 per spikelet, (1.9–)2–2.5 mm; body dark brown with paler center, lenticular, broadly ellipsoid to orbicular, 1.6–2 × 1.5–1.6 mm, margins flowing to tubercle; tubercle lowtriangular, 0.5 mm, often apiculate. |
2n | = 12. |
|
Rhynchospora latifolia |
Rhynchospora ciliaris |
|
Phenology | Fruiting late spring–summer. | Fruiting late spring–fall. |
Habitat | Sands and peats of bogs in pine savannas and flatwoods | Sands and peats in bogs, seeps, depressions in savannas, and low open pinelands |
Elevation | 0–200 m (0–700 ft) | 0–100 m (0–300 ft) |
Distribution |
AL; FL; GA; LA; MS; NC; SC; TX
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AL; FL; GA; LA; MS; NC; SC
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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.) |
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Source | FNA vol. 23. | FNA vol. 23, p. 237. |
Parent taxa | Cyperaceae > Rhynchospora | Cyperaceae > Rhynchospora |
Sibling taxa | ||
Synonyms | Dichromena latifolia, R. stellata var. latifolia | Schoenus ciliaris, Phaeocephalum ciliatum, R. ciliata, R. rappiana |
Name authority | (Baldwin) W. W. Thomas: Mem. New York Bot. Gard. 37: 86. (1984) | (Michaux) C. Mohr: Contr. U.S. Natl. Herb. 6: 408. (1901) |
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