Rhynchospora caduca |
Rhynchospora microcarpa |
|
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anglestem beaksedge |
southern beaksedge |
|
Habit | Plants perennial, cespitose, 70–150 cm; rhizomes often present, short, scaly. | Plants perennial, cespitose, to 100 cm; rhizomes absent. |
Culms | erect or ascending, leafy, trigonous. |
erect to ascending, arching, lax, leafy, slender, trigonous. |
Leaves | exceeded by culm; blades linear, proximally 4–7 mm wide, apex trigonous, tapering. |
exceeded by inflorescence; blades ascending to spreading, linear, proximally flat, 1–2(–3) mm wide, apex trigonous, subulate, tapering. |
Inflorescences | terminal and axillary; clusters 3–6, mostly dense, narrowly to broadly turbinate, branches ascending; leafy bracts exceeeding proximalmost inflorescences. |
spikelet clusters 4–6, mostly dense, widely spaced, narrowly turbinate to ellipsoid; peduncles erect to ascending, branches ascending; leafy bracts exceeding proximal clusters. |
Spikelets | rich brown, ovoid, (3–)4–5 mm, apex acuminate; fertile scales ovate, 2.5–3.5 mm, apex acuminate, midrib included or shortexcurrent. |
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 mostly 6, exceeding tubercle tip. |
perianth bristles 6, from vestigial to (rarely) reaching tubercle tip, antrorsely barbellate. |
Fruits | 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. |
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 caduca |
Rhynchospora microcarpa |
|
Phenology | Fruiting summer–fall. | Fruiting late spring–fall or all year (south). |
Habitat | Low meadows, clearings, marshes, marsh borders, seeps, bog moats, savannas, ditches, pine flatwoods, swamps | Savanna swales, interdunal marshes, broad marshes, wet glades, bog edges, open swamp forests, pond shores |
Elevation | 0–400 m (0–1300 ft) | 0–100 m (0–300 ft) |
Distribution |
AL; AR; FL; GA; LA; MS; NC; OK; SC; TN; TX; VA
|
AL; FL; GA; LA; MS; NC; SC; TX; West Indies |
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.) |
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. 223. | FNA vol. 23, p. 228. |
Parent taxa | Cyperaceae > Rhynchospora | Cyperaceae > Rhynchospora |
Sibling taxa | ||
Synonyms | Phaeocephalum caducum, R. patula | Phaeocephalum microcarpum, Phaeocephalum patulum, R. edisoniana, R. sulcata, R. torreyana var. microrhyncha |
Name authority | Elliott: Sketch Bot. S. Carolina 1: 62. (1816) | Baldwin ex A. Gray: Ann. Lyceum Nat. Hist. New York 3: 202. (1835) |
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