Rhynchospora megaplumosa |
Rhynchospora microcephala |
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manatee beaksedge |
smallhead beaksedge |
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Habit | Plants perennial, cespitose, 20–90 cm, base pale brown to dark brown; rhizomes absent or compact, knotty, scaly. | Plants perennial, cespitose, 30–90 cm; rhizomes absent. |
Culms | erect to arching-ascending, leafy, wand-like. |
arching or erect, leafy, nearly terete, multiribbed, slender. |
Leaves | mostly basal, few and increasingly distant upculm, shorter than scape; blades narrowly linear, concave proximally, (1–)2–3 mm wide, tapering and increasingly involute-sulcate proximally, margins scabrid, apex triquetrous, tip narrow but blunt. |
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Inflorescences | clusters 1(–2), if 2 then close together, dense, broadly turbinate to hemispheric; primary leafy bracts linear, stiff, exceeding clusters. |
spikelet clusters 2–6, mostly widely spaced; clusters dense, hemispheric to mostly spheroid, 0.5–1 cm thick. |
Spikelets | light brown, narrowly lanceoloid, 8–10 mm, apex acuminate; fertile scales lanceolate, convex, (6–)7–8 mm, apex narrowly acute, low midrib short-excurrent or not. |
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, excurved, plumose from base to midbristle, 5–7.5 mm, antrorsely barbellate to tip. |
perianth bristles 6, reaching tubercle tip, retrorsely barbellate. |
Fruits | 1–2 per spikelet, 2.3–2.6 × 1.1–1.2 mm; body brown, short-stipitate, tumidly obovoid, subterete, 1.8–2 mm, margin low, broad; surfaces interruptedly transversely wavy-rugulose; tubercle broadly and concavely conic, 0.5–0.7 mm high, base shallowly 2-lobed, discoid, abruptly narrowed to blunt tip. |
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, proximally flattened, 1–3 mm wide, apex tapering, trigonous. |
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Rhynchospora megaplumosa |
Rhynchospora microcephala |
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Phenology | Fruiting spring–fall or all year. | Fruiting summer–fall. |
Habitat | Sands and sandy peats of pine flatwoods scrub and flatwoods-sandscrub transition | Sands and sandy peats of savanna swales, pineland seeps, bogs, ditches, pond shores and banks |
Elevation | 0–50 m (0–200 ft) | 0–200 m (0–700 ft) |
Distribution |
FL |
AL; DC; DE; FL; GA; LA; MD; MS; NC; NJ; SC; VA; West Indies (Cuba)
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Discussion | Of conservation concern. Rhynchospora megaplumosa is local in central peninsular Florida. It often shares habitat with R. pineticola, and it is taxonomically nearest it in series Plumosae. Distinctive are the longer, paler, narrower spikelets, the longer fertile scales, and perianth bristles of R. megaplumosa. In fact, the perianth bristles of R. megaplumosa are the longest known in the series. While the bristles of all other Plumosae are erect, hugging the achene body, those of R. megaplumosa bend outward so strongly that they push away subtending scales; bristles are conspicuously exposed at maturity. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 23, p. 218. | FNA vol. 23, p. 213. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | R. axillaris var. microcephala, R. cephalantha var. microcephala | |
Name authority | E. L. Bridges & Orzell: Lundellia 3: 20, fig. 1. (2000) | (Britton) Britton ex Small: Fl. S.E. U.S., 195. (1903) |
Web links |