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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
from FNA
AL; FL; GA; LA; MS; NC; SC; TX
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; FL; GA; LA; MS; NC; SC
[WildflowerSearch map]
[BONAP county map]
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. 237.
Parent taxa Cyperaceae > Rhynchospora Cyperaceae > Rhynchospora
Sibling taxa
R. alba, R. baldwinii, R. brachychaeta, R. breviseta, R. caduca, R. californica, R. capillacea, R. capitellata, R. careyana, R. cephalantha, R. chalarocephala, R. chapmanii, R. ciliaris, R. colorata, R. compressa, R. corniculata, R. crinipes, R. curtissii, R. debilis, R. decurrens, R. divergens, R. elliottii, R. eximia, R. fascicularis, R. fernaldii, R. filifolia, R. floridensis, R. fusca, R. globularis, R. glomerata, R. gracilenta, R. grayi, R. harperi, R. harveyi, R. indianolensis, R. inexpansa, R. inundata, R. knieskernii, R. kunthii, R. macra, R. macrostachya, R. megalocarpa, R. megaplumosa, R. microcarpa, R. microcephala, R. miliacea, R. mixta, R. nitens, R. nivea, R. odorata, R. oligantha, R. pallida, R. perplexa, R. pineticola, R. pleiantha, R. plumosa, R. punctata, R. pusilla, R. rariflora, R. recognita, R. scirpoides, R. solitaria, R. stenophylla, R. thornei, R. torreyana, R. tracyi, R. wrightiana
R. alba, R. baldwinii, R. brachychaeta, R. breviseta, R. caduca, R. californica, R. capillacea, R. capitellata, R. careyana, R. cephalantha, R. chalarocephala, R. chapmanii, R. colorata, R. compressa, R. corniculata, R. crinipes, R. curtissii, R. debilis, R. decurrens, R. divergens, R. elliottii, R. eximia, R. fascicularis, R. fernaldii, R. filifolia, R. floridensis, R. fusca, R. globularis, R. glomerata, R. gracilenta, R. grayi, R. harperi, R. harveyi, R. indianolensis, R. inexpansa, R. inundata, R. knieskernii, R. kunthii, R. latifolia, R. macra, R. macrostachya, R. megalocarpa, R. megaplumosa, R. microcarpa, R. microcephala, R. miliacea, R. mixta, R. nitens, R. nivea, R. odorata, R. oligantha, R. pallida, R. perplexa, R. pineticola, R. pleiantha, R. plumosa, R. punctata, R. pusilla, R. rariflora, R. recognita, R. scirpoides, R. solitaria, R. stenophylla, R. thornei, R. torreyana, R. tracyi, R. wrightiana
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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