Rhynchospora curtissii |
Rhynchospora cephalantha |
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Curtiss' beaksedge |
bunched beaksedge |
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Habit | Plants perennial, densely cespitose, 10–30 cm; rhizomes absent. | Plants perennial, cespitose, 40–100(–150) cm; rhizomes absent. |
Culms | lax, erect to excurved, leafy toward base, filiform. |
arching, leafy, obscurely and convexly trigonous, multi-ribbed, slender to stoutish. |
Leaves | overtopped by scape; blades filiform, distally flattened, channeled, tapering, to 1 mm wide, margins strongly involute, apex blunt. |
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Inflorescences | spikelet clusters 1–3, laterals widely spaced, all narrowly turbinate, ellipsoid, or ovoid; leafy bracts setaceous, overtopping proximal clusters, often overtopped by terminal ones. |
spikelet clusters 3–several, widely spaced, often equidistant, mostly hemispheric to globose, occasionally lobed, 1–2 cm thick; bracteal leaves much exceeding subtended inflorescence. |
Spikelets | erect or ascending, redbrown, lanciform, mostly 4.5–5 mm, apex acute; fertile scales lanceolate, (3–)4–4.5 mm, apex acute, apiculate. |
dark red-brown to dark brown, lanceellipsoid to ellipsoid, 4–5(–6) mm, apex acute; fertile scales elliptic, 3–3.5(–4.5) mm, apex acute, midribs 3, laterals indistinct. |
Flowers | perianth absent. |
perianth bristles 6, reaching tubercle tip, retrorsely (rarely antrorsely) barbellate. |
Fruits | 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. |
1(–2) per spikelet, 3.5–4(–4.2) mm; body brown with pale center, obovoid distal to stipe, lenticular, 2–2.3 × 1–1.5(–2) mm; tubercle triangular-subulate, (1–)1.5–2 mm, at least 0.5 mm wide at base. |
Principal | leaves overtopped by culm; blades linear, flat proximally, 1.5–3 mm wide, apex tapering, trigonous. |
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Rhynchospora curtissii |
Rhynchospora cephalantha |
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Phenology | Fruiting summer–fall. | Fruiting summer–fall. |
Habitat | Sands and peats of bogs, pineland pond shores, seeps, and low moist savannas | Sandy silts, sands, and peats of shores, boggy streams, seeps, savannas, and savanna bogs |
Elevation | 0–100 m (0–300 ft) | 0–200 m (0–700 ft) |
Distribution |
AL; FL; MS |
AL; DE; FL; GA; LA; MD; MS; NC; NJ; NY; SC; TX; VA
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Discussion | North American plants referred to Rhynchospora axillaris (Lamarck) Britton [Phaeocephala axillare (Lamarck) House by N. L. Britton and A. Brown (1913) and J. K. Small (1933)] are actually R. cephalantha. A photograph of the type specimen of Schoenus axillaris Lamarck (from P) reveals what appears to be an immature top of S. glomeratus [R. glomerata (Linnaeus) Vahl]. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 23, p. 234. | FNA vol. 23, p. 212. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Phaeocephalum curtissii, R. filifolia var. ellipsoidea | R. cephalantha var. attenuata, R. cephalantha var. pleiocephala |
Name authority | Britton: in J. K. Small, Fl. S.E. U.S., 195, 1327. (1903) | A. Gray: Ann. Lyceum Nat. Hist. New York 3: 218. (1835) |
Web links |