Rhynchospora divergens |
Rhynchospora inundata |
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spreading beaksedge |
inundated beakrush, narrow-fruit beaksedge, narrowfruit horned beaksedge |
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Habit | Plants perennial, densely cespitose, 10–60 cm; rhizomes absent. | Plants perennial, clonal, 50–100 cm; rhizomes slender, scaly, to 2 mm thick. |
Culms | erect or spreadingarching, linearfiliform, terete, leafy toward base. |
stiffly erect, leafy, triangular, multiribbed. |
Leaves | overtopped by culm; blades ascending, filiform, 0.3–0.5 mm wide, margins deeply involute, then channeled, apex trigonous, setaceous. |
erect, distal ones overtopping inflorescence; principal blades flat proximally, trigonous distally, 3–10 mm wide, apex attenuate. |
Inflorescences | spikelet clusters 1–2(–4), dense(–open), narrowly to broadly turbinate; branches capillary, variously elongate; leafy bracts setaceous, proximal exceeding clusters. |
terminal and axillary, clusters of corymbs (1–)2–3, open, spikelet clusters loose; bracteal leaves mostly overtopping corymbs. |
Spikelets | 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. |
pale redbrown, narrowly lanceoloid, (9–)11–14 mm, apex acuminate; fertile scales lanceolate, 9–13 mm, apex acuminate, midrib shortexcurrent or not. |
Flowers | perianth absent. |
perianth bristles 5–6, extending at least 5 mm beyond tubercle base, antrorsely barbellate. |
Fruits | 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. |
1–2 per spikelet, 15–20 mm; body stipitate, obovoid to oblong, compressed, 4–5 × 2–3 mm, margins thick; surfaces concave, horizontally finely striate, minutely cancellate; tubercle stoutbased, grooved, subulate, 10–15 mm, setulose. |
Rhynchospora divergens |
Rhynchospora inundata |
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Phenology | Fruiting summer–fall or all year (south). | Fruiting summer–fall. |
Habitat | Moist sands, peats, silts or clays of low meadows, bogs, flatwoods, sometimes seeps over calcareous rock | Emergent in shallows of savanna ponds, interdunal pools |
Elevation | 0–300 m (0–1000 ft) | 0–100 m (0–300 ft) |
Distribution |
AL; FL; GA; LA; MS; NC; SC; TX; Central America; West Indies (Bahamas, Cuba, Dominican Republic) |
AL; DE; FL; GA; LA; MA; MD; MS; NC; NJ; NY; RI; SC; VA
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Discussion | Rhynchospora inundata is largely confined to lower Coastal Plain terraces, mostly along the present coast. Typical plants have narrow fruit bodies and narrow inflorescences of sparse clusters, well overtopped by leaves and erect leafy bracts. By contrast, plants of R. careyana have broader fruits, shorter perianths, and larger, broader inflorescences that overtop most or all leaves and bracts. In general, plants of R. careyana are more robust and grow in more acid sites than those of R. inundata. Southward in the Atlantic Coastal and Gulf Coastal plains are broad areas of ecotone where the two species intergrade. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 23, p. 220. | FNA vol. 23, p. 208. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Ceratoschoenus macrostachyus var. inundatus, R. macrostachya var. inundata | |
Name authority | Chapman ex M. A. Curtis: Amer. J. Sci. Arts, ser. 2, 7: 409. (1849) | (Oakes) Fernald: Rhodora 20: 139. (1918) |
Web links |