Rhynchospora caduca |
Rhynchospora nitens |
|
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anglestem beaksedge |
short-beak beaksedge, shortbeak bald-rush |
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Habit | Plants perennial, cespitose, 70–150 cm; rhizomes often present, short, scaly. | Plants annual, cespitose or solitary, (10–)20–100 cm; rhizomes absent. |
Culms | erect or ascending, leafy, trigonous. |
erect, leafy, nearly terete or angled, manyribbed. |
Leaves | exceeded by culm; blades linear, proximally 4–7 mm wide, apex trigonous, tapering. |
|
Inflorescences | terminal and axillary; clusters 3–6, mostly dense, narrowly to broadly turbinate, branches ascending; leafy bracts exceeeding proximalmost inflorescences. |
terminal and axillary, clusters of corymbs 1–5, usually diffuse; leafy bracts exceeding proximal corymbs. |
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, lanceoloid to ovoid, mostly 4–6(–8) mm, apex acute; fertile scales many, ovate, rounded-convex, 2–3.5 mm, apex acute, midrib mostly included, rarely forming apiculus. |
Flowers | perianth bristles mostly 6, exceeding tubercle tip. |
perianth absent. |
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. |
1–1.3(–1.5) mm, body dark brown, tumidly lenticular, nearly orbicular, 0.7–1 × 0.7–1 mm, margins strong, interrupted at tubercle base; surfaces irregularly transversely rugulose with wavy rows of vertical, linear, raised cells; tubercle depressed-triangular, 0.1–0.3 mm, capping fruit summit, base broadly 2lobed. |
Principal | midculm leaves often exceeding inflorescences; blades linear, proximally flattened, 1–5 mm wide, apex trigonous, tapering. |
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Rhynchospora caduca |
Rhynchospora nitens |
|
Phenology | Fruiting summer–fall. | Fruiting summer–fall or all year. |
Habitat | Low meadows, clearings, marshes, marsh borders, seeps, bog moats, savannas, ditches, pine flatwoods, swamps | Moist to wet sands or peats of stream banks, pond shores, depressions in savannas, marshes |
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; DE; FL; GA; IN; LA; MA; MI; MS; NC; NJ; NY; SC; TX; VA; Central America; West Indies
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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. 223. | FNA vol. 23, p. 217. |
Parent taxa | Cyperaceae > Rhynchospora | Cyperaceae > Rhynchospora |
Sibling taxa | ||
Synonyms | Phaeocephalum caducum, R. patula | Scirpus nitens, Isolepis nitens, Psilocarya nitens, Psilocarya rhynchosporoides |
Name authority | Elliott: Sketch Bot. S. Carolina 1: 62. (1816) | (Vahl) A. Gray: Manual ed. 5, 568. (1867) |
Web links |