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featherbristle beaksedge

Curtiss' beaksedge

Habit Plants perennial, densely cespitose, knottybased, 20–40 cm; rhizomes absent. Plants perennial, densely cespitose, 10–30 cm; rhizomes absent.
Culms

filiform, leafy at base, wiry.

lax, erect to excurved, leafy toward base, filiform.

Leaves

ascending to erect;

blades filiform, nearly terete, or channeled, sometimes compressed, nearly reaching distal inflorescence or much shorter, 0.2–0.3 mm thick, apex subulate.

overtopped by scape;

blades filiform, distally flattened, channeled, tapering, to 1 mm wide, margins strongly involute, apex blunt.

Inflorescences

spikelet clusters 2–6, simple or reduced to 1 spikelet, branches ascending to divaricate or reflexed; leafy bracts single per cluster, filiform, setaceous, with clusters appearing lateral to bracts.

spikelet clusters 1–3, laterals widely spaced, all narrowly turbinate, ellipsoid, or ovoid; leafy bracts setaceous, overtopping proximal clusters, often overtopped by terminal ones.

Spikelets

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

fertile scales oblongelliptic, convex, acuminate, 3.5–5 mm, apex broadly acute, midrib forming apiculus.

erect or ascending, redbrown, lanciform, mostly 4.5–5 mm, apex acute;

fertile scales lanceolate, (3–)4–4.5 mm, apex acute, apiculate.

Flowers

perianth bristles 6, reaching to or slightly past tubercle base, increasingly plumose from middle to base.

perianth absent.

Fruits

1–3 per spikelet, (2.5–)2.7–3(–3.4) mm;

body light brown to brown, ellipsoidobovoid, distally conspicuously necked, tumidly lenticular, 1.7–2.5 × 1.5–1.8 mm;

surfaces smooth or minutely transversely rugulose;

tubercle conicsubulate, 0.5–0.7 mm, base flaring.

2–3(–5) per spikelet;

stipe and receptacle 0.1–0.2(–0.3) mm, setose;

body brown with pale glassy center, narrowly obovoidellipsoid, lenticular, 1.2–1.5 mm, margins narrow, flowing to tubercle;

surfaces very finely lined longitudinally, transversely with wavy lines of tiny pits;

tubercle narrowly triangular or slightly concavesided, flattened, 0.7–1.2(–1.5) mm.

Rhynchospora oligantha

Rhynchospora curtissii

Phenology Fruiting spring–summer. Fruiting summer–fall.
Habitat Sands and peats of bogs, depressions in savannas, open pinelands, seeps Sands and peats of bogs, pineland pond shores, seeps, and low moist savannas
Elevation 0–200 m (0–700 ft) 0–100 m (0–300 ft)
Distribution
from FNA
AL; DC; DE; FL; GA; LA; MS; NC; NJ; SC; TX; VA; Central America; West Indies
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; FL; MS
[BONAP county map]
Discussion

Rhynchospora oligantha is distinguished from other taxa of its complex mostly by the distinctive neck at the achene apex, a feature essentially absent in R. breviseta, its closest relative. Those two species have been heavily impacted by conversion of pine savannas to cropland or pine plantations; even with abandonment or clearing of such land, they are very slow to reoccupy the disturbed sites.

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

Source FNA vol. 23, p. 218. FNA vol. 23, p. 234.
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. latifolia, R. macra, R. macrostachya, R. megalocarpa, R. megaplumosa, R. microcarpa, R. microcephala, R. miliacea, R. mixta, R. nitens, R. nivea, R. odorata, 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. ciliaris, R. colorata, R. compressa, R. corniculata, R. crinipes, 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 Phaeocephalum curtissii, R. filifolia var. ellipsoidea
Name authority A. Gray: Ann. Lyceum Nat. Hist. New York 3: 212. (1835) Britton: in J. K. Small, Fl. S.E. U.S., 195, 1327. (1903)
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