Rhynchospora inundata |
Rhynchospora microcarpa |
|
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inundated beakrush, narrow-fruit beaksedge, narrowfruit horned beaksedge |
southern beaksedge |
|
Habit | Plants perennial, clonal, 50–100 cm; rhizomes slender, scaly, to 2 mm thick. | Plants perennial, cespitose, to 100 cm; rhizomes absent. |
Culms | stiffly erect, leafy, triangular, multiribbed. |
erect to ascending, arching, lax, leafy, slender, trigonous. |
Leaves | erect, distal ones overtopping inflorescence; principal blades flat proximally, trigonous distally, 3–10 mm wide, apex attenuate. |
exceeded by inflorescence; blades ascending to spreading, linear, proximally flat, 1–2(–3) mm wide, apex trigonous, subulate, tapering. |
Inflorescences | terminal and axillary, clusters of corymbs (1–)2–3, open, spikelet clusters loose; bracteal leaves mostly overtopping corymbs. |
spikelet clusters 4–6, mostly dense, widely spaced, narrowly turbinate to ellipsoid; peduncles erect to ascending, branches ascending; leafy bracts exceeding proximal clusters. |
Spikelets | pale redbrown, narrowly lanceoloid, (9–)11–14 mm, apex acuminate; fertile scales lanceolate, 9–13 mm, apex acuminate, midrib shortexcurrent or not. |
dark brown, ovoid, 2–3 mm, apex acute; fertile scales broadly ovate to ± orbiculate, cupulate, 1.5–2 mm, apex rounded to acute, midrib included or excurrent as bristle. |
Flowers | perianth bristles 5–6, extending at least 5 mm beyond tubercle base, antrorsely barbellate. |
perianth bristles 6, from vestigial to (rarely) reaching tubercle tip, antrorsely barbellate. |
Fruits | 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. |
2–3 per spikelet, 1.2–1.5 mm; body brown, obovoid to globose, lenticular, 1–1.2 × 0.8–1 mm, margins narrow, distinct; surfaces sharply transversely wavyrugose, intervals with rows of vertical, broadly rectangular or ± isodiametric alveolae; tubercle lowtriangular or triangular, compressed, 0.2–0.3 mm, base lunate. |
Rhynchospora inundata |
Rhynchospora microcarpa |
|
Phenology | Fruiting summer–fall. | Fruiting late spring–fall or all year (south). |
Habitat | Emergent in shallows of savanna ponds, interdunal pools | Savanna swales, interdunal marshes, broad marshes, wet glades, bog edges, open swamp forests, pond shores |
Elevation | 0–100 m (0–300 ft) | 0–100 m (0–300 ft) |
Distribution |
AL; DE; FL; GA; LA; MA; MD; MS; NC; NJ; NY; RI; SC; VA
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AL; FL; GA; LA; MS; NC; SC; TX; West Indies |
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.) |
Through much of the range of Rhynchospora microcarpa, particularly in limesink or claybased pond areas, is a somewhat shorter series of plants with narrow leaves, tumid fruit 0.7–0.9 mm, often with isodiametric alveolae and depressedtriangular tubercles. Described by S. Gale as R. sulcata, the plants grade into the more typical morphology for R. microcarpa. In peninsular Florida, apparent intergradation with R. elliottii produces some individuals with broad leaves and triangularsubulate tubercles on nearly flat fruits. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 208. | FNA vol. 23, p. 228. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Ceratoschoenus macrostachyus var. inundatus, R. macrostachya var. inundata | Phaeocephalum microcarpum, Phaeocephalum patulum, R. edisoniana, R. sulcata, R. torreyana var. microrhyncha |
Name authority | (Oakes) Fernald: Rhodora 20: 139. (1918) | Baldwin ex A. Gray: Ann. Lyceum Nat. Hist. New York 3: 202. (1835) |
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