Rhynchospora latifolia |
Rhynchospora recognita |
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sandswamp whitetop |
globe beaksedge |
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Habit | Plants perennial, cespitose or solitary, to 100 cm; rhizomes scaly, 3–4 mm thick. | Plants perennial, cespitose, 60–100(–120) cm; rhizomes absent. |
Culms | arching or erect, leafy-based, distally wandlike, terete, multiribbed. |
leafiest at base, trigonous, slender, somewhat stiff. |
Leaves | ascending to spreading, overtopped by scape; blades linear, proximally flat, 2.5–5 mm wide, apex subulate, trigonous. |
exceeded by culms; basal blades spreading, blunt, distal ascending, linear, proximally flat, 2–5 mm wide, apex trigonous, subulate, 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. |
spikelet clusters 3–5 or more, compact, proximalmost widely spaced, turbinate to hemispheric or lobed; peduncles ascending, branches ascending; leafy bracts setaceous at apex, exceeding compounds, setaceous bracts often exceeding ultimate clusters, imparting bristly aspect. |
Spikelets | white, ovoid, 5–7 mm; fertile scales boatshaped, sharply curved-keeled, 5 mm, apex acute. |
redbrown, ovoid to lanceoloid, (2.7–)3–4 mm, apex acuminate; fertile scales ovate, 2.5–3 mm, apex acute, shortacuminate, or notched, midrib usually excurrent as cusp or awn. |
Flowers | perianth absent. |
perianth bristles 6, not reaching further than fruit midbody. |
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. |
1–3 per spikelet, (1.8–)2–2.3(–2.5) mm; body brown, tumidly lenticular, obovoid to suborbicular, 1.4–1.6(–1.8) × 1.2–1.5 mm; surfaces transversely sharply rugose, intervals of rows of vertical, variously rectangular alveolae; tubercle somewhat compressed, triangular to shortconic, 0.5–0.7 mm, shortsubulate, basal rim often present. |
2n | = 12. |
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Rhynchospora latifolia |
Rhynchospora recognita |
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Phenology | Fruiting late spring–summer. | Fruiting spring–summer(–early fall). |
Habitat | Sands and peats of bogs in pine savannas and flatwoods | Sands, silts, clays, and peats of low meadows, ditches, low clearings, savannas |
Elevation | 0–200 m (0–700 ft) | 0–400 m (0–1300 ft) |
Distribution |
AL; FL; GA; LA; MS; NC; SC; TX
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AL; AR; CA; DC; DE; FL; GA; IL; IN; KS; KY; LA; MD; MI; MO; MS; NC; NJ; OK; PA; SC; TN; TX; VA; WV; Central America; West Indies
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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.) |
Rhynchospora recognita has larger fruit and tubercles than is consistent with the varietal rank it has held under R. globularis. The two are often observed in the same locality, and in such cases, R. recognita is taller, stiffer, broader leaved, with spikelet clusters wider, denser, and bristlier, and with distinct orange tints in comparison with the darker, less dense, narrower, and less bristly spikelet clusters of plants of R. globularis. (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. globularis var. recognita, Dichromena cymosa, Phaeocephalum cymosum |
Name authority | (Baldwin) W. W. Thomas: Mem. New York Bot. Gard. 37: 86. (1984) | (Gale) Kral: Novon 9: 205. (1999) |
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