Rhynchospora cephalantha |
Rhynchospora microcephala |
|
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bunched beaksedge |
smallhead beaksedge |
|
Habit | Plants perennial, cespitose, 40–100(–150) cm; rhizomes absent. | Plants perennial, cespitose, 30–90 cm; rhizomes absent. |
Culms | arching, leafy, obscurely and convexly trigonous, multi-ribbed, slender to stoutish. |
arching or erect, leafy, nearly terete, multiribbed, slender. |
Inflorescences | spikelet clusters 3–several, widely spaced, often equidistant, mostly hemispheric to globose, occasionally lobed, 1–2 cm thick; bracteal leaves much exceeding subtended inflorescence. |
spikelet clusters 2–6, mostly widely spaced; clusters dense, hemispheric to mostly spheroid, 0.5–1 cm thick. |
Spikelets | 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. |
dark redbrown to dark brown, lanceovoid, (2–)2.5–3.5(–4) mm, apex acute; fertile scales elliptic, 2–3 mm, apex acute, midrib shortexcurrent or not. |
Flowers | perianth bristles 6, reaching tubercle tip, retrorsely (rarely antrorsely) barbellate. |
perianth bristles 6, reaching tubercle tip, retrorsely barbellate. |
Fruits | 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. |
1 per spikelet, 2.5–3 mm; body pale brown with light center, lenticular, obovoid distal to stipe, 1.1–1.5 × 0.9–1.1 mm, margins pale, wirelike, surfaces slick; tubercle triangularsubulate, 0.9–1.2(–1.5) 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. |
leaves overtopped by culm; blades linear, proximally flattened, 1–3 mm wide, apex tapering, trigonous. |
Rhynchospora cephalantha |
Rhynchospora microcephala |
|
Phenology | Fruiting summer–fall. | Fruiting summer–fall. |
Habitat | Sandy silts, sands, and peats of shores, boggy streams, seeps, savannas, and savanna bogs | Sands and sandy peats of savanna swales, pineland seeps, bogs, ditches, pond shores and banks |
Elevation | 0–200 m (0–700 ft) | 0–200 m (0–700 ft) |
Distribution |
AL; DE; FL; GA; LA; MD; MS; NC; NJ; NY; SC; TX; VA
|
AL; DC; DE; FL; GA; LA; MD; MS; NC; NJ; SC; VA; West Indies (Cuba)
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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.) |
|
Source | FNA vol. 23, p. 212. | FNA vol. 23, p. 213. |
Parent taxa | Cyperaceae > Rhynchospora | Cyperaceae > Rhynchospora |
Sibling taxa | ||
Synonyms | R. cephalantha var. attenuata, R. cephalantha var. pleiocephala | R. axillaris var. microcephala, R. cephalantha var. microcephala |
Name authority | A. Gray: Ann. Lyceum Nat. Hist. New York 3: 218. (1835) | (Britton) Britton ex Small: Fl. S.E. U.S., 195. (1903) |
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