Rhynchospora gracilenta |
Rhynchospora microcephala |
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slender beaksedge |
smallhead beaksedge |
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Habit | Plants perennial, densely cespitose or solitary, 10–100 cm; rhizomes absent. | Plants perennial, cespitose, 30–90 cm; rhizomes absent. |
Culms | mostly lax, ascending to leaningexcurved, leafy, linear to filiform, terete. |
arching or erect, leafy, nearly terete, multiribbed, slender. |
Leaves | shorter than culm; blades ascending, filiform to narrowly linear, proximally flat, 0.5–1.5(–2.5) mm wide, margins distally strongly involute, apex trigonous, tapering. |
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Inflorescences | spikelet clusters 1–3(–4), proximalmost distant, dense to sparse, narrowly turbinate to hemispheric; peduncles and branches ascending; leafy bracts linearsetaceous, mostly overtopping clusters. |
spikelet clusters 2–6, mostly widely spaced; clusters dense, hemispheric to mostly spheroid, 0.5–1 cm thick. |
Spikelets | redbrown, ovoid to lanceoloid, (3.5–)4–5 mm, apex acute; fertile scales ovate, 3–4.5 mm, apex acute, mucronate to awnedcuspidate. |
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 | bristles 6, mostly reaching tip of tubercle or beyond, antrorsely barbellate. |
perianth bristles 6, reaching tubercle tip, retrorsely barbellate. |
Fruits | 1–3 per spikelet, (2.5–)3–3.5(–4.1) mm; body dark brown with small pale center, lenticular, broadly ellipsoid to suborbicular, 1.3–2.1 × 1.3–1.5 mm, smooth, margins narrow, flowing into tubercle; tubercle triangular-subulate, compressed, mostly 1.5–2 mm. |
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 gracilenta |
Rhynchospora microcephala |
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Phenology | Fruiting late spring–fall. | Fruiting summer–fall. |
Habitat | Moist to wet sandy peaty substrates in ditches, bogs, seeps, wet savannas, barrens, and flatwoods | Sands and sandy peats of savanna swales, pineland seeps, bogs, ditches, pond shores and banks |
Elevation | 0–400 m (0–1300 ft) | 0–200 m (0–700 ft) |
Distribution |
AL; AR; DE; FL; GA; LA; MD; MS; NC; NJ; OK; PA; SC; TN; TX; VA; Central America; West Indies (Cuba)
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AL; DC; DE; FL; GA; LA; MD; MS; NC; NJ; SC; VA; West Indies (Cuba)
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Discussion | Through the southern coastal plain are widerleaved examples of Rhynchospora gracilenta that are sparingly cespitose to solitary-stemmed, often with but a single terminal inflorescence with dense clusters of spikelets (var. diversifolia). That would be a tenable designation were it not for the large numbers of populations with intermediate habit. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 23, p. 236. | FNA vol. 23, p. 213. |
Parent taxa | Cyperaceae > Rhynchospora | Cyperaceae > Rhynchospora |
Sibling taxa | ||
Synonyms | Phaeocephalum gracilentum, R. drummondiana, R. gracilenta var. diversifolia, R. trichophylla | R. axillaris var. microcephala, R. cephalantha var. microcephala |
Name authority | A. Gray: Ann. Lyceum Nat. Hist. New York 3: 216. (1835) | (Britton) Britton ex Small: Fl. S.E. U.S., 195. (1903) |
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