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sandswamp whitetop

Habit Plants perennial, cespitose or solitary, to 100 cm; rhizomes scaly, 3–4 mm thick. Plants perennial, densely cespitose, knottybased, 20–40 cm; rhizomes absent.
Culms

arching or erect, leafy-based, distally wandlike, terete, multiribbed.

leafy at base, filiform, wiry.

Leaves

ascending to spreading, overtopped by scape;

blades linear, proximally flat, 2.5–5 mm wide, apex subulate, trigonous.

blades filiform, nearly reaching inflorescence tip or much shorter, to 0.3 mm thick, apex 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 mostly 2–6, simple or reduced to 1 spikelet, often with 2 capillary branches, one divaricate or reflexed, 1 ascending; leafy bracts single per cluster, filiform, setaceous, with clusters appearing lateral to bracts.

Spikelets

white, ovoid, 5–7 mm;

fertile scales boatshaped, sharply curved-keeled, 5 mm, apex acute.

pale redbrown, ellipsoidlanceoloid, 5–6(–8) mm, apex acute to acuminate;

fertile scales narrowly ovate, 3–5(–6) mm, apex acute, midrib included or shortexcurrent.

Flowers

perianth absent.

perianth bristles 6, not reaching past fruit midbody, stubby, plumose to near tip.

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.

3–8 per spikelet, 2–2.5 mm;

body light brown to brown, ellipsoid-obovoid, tumidly lenticular, 1.5–2 × 1.6–1.7 mm;

surfaces faintly, interruptedly crossrugulose, apically indented under tubercle;

tubercle lowconic, 0.5 mm, base flaring, circular.

2n

= 12.

Rhynchospora latifolia

Rhynchospora breviseta

Phenology Fruiting late spring–summer. Fruiting spring–summer.
Habitat Sands and peats of bogs in pine savannas and flatwoods Moist to wet sands or peats of bogs, depressions in savannas, open pinelands, pond shores
Elevation 0–200 m (0–700 ft) 0–200 m (0–700 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; VA; West Indies
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 breviseta is sympatric with R. oligantha over much of its range; intergrades have not been seen.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 23. FNA vol. 23.
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. 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. 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 R. oligantha var. breviseta
Name authority (Baldwin) W. W. Thomas: Mem. New York Bot. Gard. 37: 86. (1984) (Gale) Channell: Rhodora 58: 336. (1956)
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