Rhynchospora fernaldii |
Rhynchospora caduca |
|
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Fernald's beaksedge |
anglestem beaksedge |
|
Habit | Plants perennial, cespitose, 15–50 cm; rhizomes absent. | Plants perennial, cespitose, 70–150 cm; rhizomes often present, short, scaly. |
Culms | erect or ascending, slender, leafy proximal to middle, somewhat stiff. |
erect or ascending, leafy, trigonous. |
Leaves | overtopped by culm; blades ascending, ± filiform, proximally flat or slightly concave, to 1 mm wide, apex narrowing, trigonous, abruptly blunt. |
exceeded by culm; blades linear, proximally 4–7 mm wide, apex trigonous, tapering. |
Inflorescences | spikelet clusters 1–2, if 2 then close together, dense, broadly turbinate to hemispheric or even globose; primary leafy bract setaceous, exceeding clusters. |
terminal and axillary; clusters 3–6, mostly dense, narrowly to broadly turbinate, branches ascending; leafy bracts exceeeding proximalmost inflorescences. |
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. |
rich brown, ovoid, (3–)4–5 mm, apex acuminate; fertile scales ovate, 2.5–3.5 mm, apex acuminate, midrib included or shortexcurrent. |
Flowers | bristles 6, some reaching to apex of fruit body. |
perianth bristles mostly 6, exceeding tubercle tip. |
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. |
mostly 3–4 per spikelet, 2–2.2 mm; body brown on short pedicellar (to 0.3 mm) stalk, broadly obovoid, lenticular, 1.3–1.5 × 1–1.5 mm, surfaces transversely rugulose, vertically finely striate and rectangularalveolate; tubercle compressed, triangular acuminate, 0.5–0.8 mm, edges setulose. |
Rhynchospora fernaldii |
Rhynchospora caduca |
|
Phenology | Fruiting summer–fall. | Fruiting summer–fall. |
Habitat | Sands and peats of low clearings in flatwoods, savannas, and bog edges | Low meadows, clearings, marshes, marsh borders, seeps, bog moats, savannas, ditches, pine flatwoods, swamps |
Elevation | 0–100 m (0–300 ft) | 0–400 m (0–1300 ft) |
Distribution |
AL; FL; GA; MS |
AL; AR; FL; GA; LA; MS; NC; OK; SC; TN; TX; VA
|
Discussion | Rhynchospora caduca has its closest relationships with the even more robust R. odorata Grisebach, on the one hand, and the swampinhabiting, more slender, and rhizomatous R. mixta Britton ex Small, on the other. Intergrades with R. odorata appear in Alabama and northwest Florida; intergrades with R. mixta appear where ranges overlap in both the Atlantic and Gulf coastal plains. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 23, p. 235. | FNA vol. 23, p. 223. |
Parent taxa | Cyperaceae > Rhynchospora | Cyperaceae > Rhynchospora |
Sibling taxa | ||
Synonyms | R. fascicularis var. fernaldii | Phaeocephalum caducum, R. patula |
Name authority | Gale: Rhodora 46: 182, plate 825, figs. 3A, B. (1944) | Elliott: Sketch Bot. S. Carolina 1: 62. (1816) |
Web links |