Rhynchospora fernaldii |
Rhynchospora filifolia |
|
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Fernald's beaksedge |
threadleaf beaksedge |
|
Habit | Plants perennial, cespitose, 15–50 cm; rhizomes absent. | Plants perennial, cespitose, 30–80(–100) cm; rhizomes absent. |
Culms | erect or ascending, slender, leafy proximal to middle, somewhat stiff. |
erect or excurved, mostly filiform, leafy proximal to midculm, obtuse-angled to subterete, wiry. |
Leaves | overtopped by culm; blades ascending, ± filiform, proximally flat or slightly concave, to 1 mm wide, apex narrowing, trigonous, abruptly blunt. |
overtopped by culm; blades narrowly linear, proximally flat, 1–2 mm wide, distally tapering-triquetrous. |
Inflorescences | spikelet clusters 1–2, if 2 then close together, dense, broadly turbinate to hemispheric or even globose; primary leafy bract setaceous, exceeding clusters. |
spikelet clusters 2–3(–4), distant, narrowly turbinate to hemispheric, mostly shorter than subtending setaceous bract. |
Spikelets | redbrown, ovoid, 2–2.5(–4) mm, apex acute; fertile scales broadly ovate, 1.5–1.9(–2) mm, apex acute to acuminate, midrib excurrent as awn to 0.5 mm. |
red-brown, lanceoloid, 2.5–3(–4) mm, apex acuminate; fertile scale elliptic, 2–2.5 mm, acute, midrib excurrent as cusp or aristula. |
Flowers | bristles 6, some reaching to apex of fruit body. |
bristles 6, reaching tubercle tip or beyond, antrorsely barbellate, base setose. |
Fruits | 2–3 per spikelet, 1–1.2(–1.4) mm; body dull dark brown with paler brown center, lenticular, broadly obovoid to broadly ellipsoid, 1 × 0.8 mm, margins narrow, flowing to tubercle; tubercle nearly equilaterally triangular, 0.2–0.3 mm. |
2–4 per spikelet, 1.5–1.7 mm, on setose pedicellar joint 0.2 mm, body with faces red-brown with pale glassy center, decurrent tubercle base; surfaces smooth; turbercle concavely triangular, 0.4–0.6 mm, setulose-ciliate. |
Rhynchospora fernaldii |
Rhynchospora filifolia |
|
Phenology | Fruiting summer–fall. | Fruiting summer–fall. |
Habitat | Sands and peats of low clearings in flatwoods, savannas, and bog edges | Sands and peats of bogs, pineland pond shores, seeps, and low savannas in pinelands |
Elevation | 0–100 m (0–300 ft) | 0–300 m (0–1000 ft) |
Distribution |
AL; FL; GA; MS |
AL; DE; FL; GA; LA; MD; MS; NC; NJ; SC; TX; VA; Central America; South America; West Indies (Cuba) |
Discussion | On the acidic, sphagnous substrates shaded by Taxodium ascendens, Nyssa biflora, and Ilex myrtifolia stands in western Florida and southern Alabama, culms of Rhynchospora filifolia reach their greatest length and are lax, leaning on other vegetation, and produce increasingly more distant clusters of spikelets that are of a paler color than is usual for the species. In fact, R. filifolia presents the greatest morphologic spectrum for its complex of species, a complex best held together by the uniformity of its fruits. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 23, p. 235. | FNA vol. 23, p. 234. |
Parent taxa | Cyperaceae > Rhynchospora | Cyperaceae > Rhynchospora |
Sibling taxa | ||
Synonyms | R. fascicularis var. fernaldii | Phaeocephalum filifolium |
Name authority | Gale: Rhodora 46: 182, plate 825, figs. 3A, B. (1944) | A. Gray: Ann. Lyceum Nat. Hist. New York 3: 366. (1836) |
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