Rhynchospora megalocarpa |
Rhynchospora divergens |
|
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sandyfield beaksedge |
spreading beaksedge |
|
Habit | Plants perennial, cespitose, to 130 cm, coarse; rhizomes scaly, stoloniferous, stout. | Plants perennial, densely cespitose, 10–60 cm; rhizomes absent. |
Culms | erect to arching, leafy, trigonous, slender, firm. |
erect or spreadingarching, linearfiliform, terete, leafy toward base. |
Leaves | overtopped by culms; blades linear, proximally flat, 3–7 mm wide, apex trigonous, subulate, tapering. |
overtopped by culm; blades ascending, filiform, 0.3–0.5 mm wide, margins deeply involute, then channeled, apex trigonous, setaceous. |
Inflorescences | spikelet clusters 2–6, sparse, widely spaced, turbinate; peduncles and branches ascending; leafy bracts exceeding proximal clusters. |
spikelet clusters 1–2(–4), dense(–open), narrowly to broadly turbinate; branches capillary, variously elongate; leafy bracts setaceous, proximal exceeding clusters. |
Spikelets | light redbrown, ovoid to ellipsoid, (4–)5–8(–9) mm, apex acute or acuminate; fertile scales ovate, (5.5–)6–6.5(–7) mm, midrib included or shortexcurrent. |
brownish, lanceellipsoid to fusiform, 2–2.5(–3) mm, apex acute; fertile scales broadly elliptic, 1.5 mm, apex narrowly rounded to broadly acute, apiculate, convexcupulate, midrib narrow, shortexcurrent or included. |
Flowers | perianth bristles 6(–8), mostly reaching from fruit midbody to tubercle base, antrorsely barbellate. |
perianth absent. |
Fruits | 1–2 per spikelet, (3.5–)4–5 mm; body dark brown to mahogany or nearly black, broadly obovoid, tumid, nearly smooth, buttressed to tubercle; tubercle lowconic, rimmed, 0.7(–1) mm, apex apiculate. |
1–3 or more per spikelet, (0.6–)0.7–0.9(–1) mm; body pale, glassy, obovoidlenticular, 0.6–0.7 × 0.4–0.5 mm, margins narrow, wirelike; surfaces finely striate, very finely reticulate; tubercle button depressedtriangular or patelliform, 0.1–0.15 mm, apiculate. |
Rhynchospora megalocarpa |
Rhynchospora divergens |
|
Phenology | Fruiting summer–fall. | Fruiting summer–fall or all year (south). |
Habitat | White or yellow sandhills | Moist sands, peats, silts or clays of low meadows, bogs, flatwoods, sometimes seeps over calcareous rock |
Elevation | 0–300 m (0–1000 ft) | 0–300 m (0–1000 ft) |
Distribution |
AL; FL; GA; MS; NC; SC
|
AL; FL; GA; LA; MS; NC; SC; TX; Central America; West Indies (Bahamas, Cuba, Dominican Republic) |
Discussion | The perianth in Rhynchospora megalocarpa is unusual. The receptacular joint is stubby, bearing staggered cycles of bristles that vary extremely in length and number—on a par with R. alba, R. baldwinii, and R. macra in numbers of bristles. The greatest extreme is twelve, the fewest as low as two; usually if the number is low, the remaining sites for bristles will be dark-colored nubbins. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 23, p. 230. | FNA vol. 23, p. 220. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Phaeocephalum dodecandrum, R. dodecrandra, R. pycnocarpa | |
Name authority | A. Gray: Ann. Lyceum Nat. Hist. New York 3: 208. (1835) | Chapman ex M. A. Curtis: Amer. J. Sci. Arts, ser. 2, 7: 409. (1849) |
Web links |