Rhynchospora caduca |
Rhynchospora harperi |
|
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anglestem beaksedge |
Harper's beaksedge |
|
Habit | Plants perennial, cespitose, 70–150 cm; rhizomes often present, short, scaly. | Plants perennial, solitary or cespitose, 50–70 cm; rhizomes absent. |
Culms | erect or ascending, leafy, trigonous. |
erect to excurved, leafybased, narrowly linear, ± terete. |
Leaves | exceeded by culm; blades linear, proximally 4–7 mm wide, apex trigonous, tapering. |
shorter than culm; blades ascending, narrowly linear, proximally flat or margins slightly involute, 0.5–1(–2) mm wide, distally canaliculate, apex trigonous, tapering, subulate. |
Inflorescences | terminal and axillary; clusters 3–6, mostly dense, narrowly to broadly turbinate, branches ascending; leafy bracts exceeeding proximalmost inflorescences. |
spikelet clusters 1–3, laterals 0–2, all turbinate to hemispheric, terminal internode usually excurved; leafy bracts setaceous, overtopping inflorescence. |
Spikelets | rich brown, ovoid, (3–)4–5 mm, apex acuminate; fertile scales ovate, 2.5–3.5 mm, apex acuminate, midrib included or shortexcurrent. |
redbrown, lanceoloid, 5–7 mm, apex acute; fertile scales lanceolate, (2.5–)4–5 mm, apex acute to acuminate; midrib paralleled by several indistinct ribs, excurrent as short awns. |
Flowers | perianth bristles mostly 6, exceeding tubercle tip. |
bristles 6, reaching from mid tubercle to beyond tip. |
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. |
3(–4) per spikelet, 2.1–2.5 mm; stipe and receptacle 0.2–0.3 mm, sparsely setose and setulose; body glossy, brown with pale center, obovoid-lenticular, 1.1–1.5 × 1–1.1 mm, surfaces finely longitudinally lined, variably low papillatecancellate, also often transversely with wavy lines of dark dots; tubercle flattened, triangular-subulate, (0.8–)0.9–1(–1.1) mm, setulose-ciliate. |
Rhynchospora caduca |
Rhynchospora harperi |
|
Phenology | Fruiting summer–fall. | Fruiting summer–fall. |
Habitat | Low meadows, clearings, marshes, marsh borders, seeps, bog moats, savannas, ditches, pine flatwoods, swamps | Sands and peats of bogs, stream banks, edges of pineland savanna ponds, Hypericum ponds |
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
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AL; DE; FL; GA; MD; MS; NC; SC; Central America (Belize)
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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.) |
Rhynchospora harperi is most abundant in a very special habitat referred to here as the “Hypericum pond.” These are typically shallow ponds in pine savannas, frequently ringed by stands of Nyssa, Taxodium, Ilex, and Cyrilla, but most of the pond itself is dominated by one or more myriandrous shrubby Hypericum species. Here R. harperi is distinguished from other species by the often abrupt bend of its ultimate internode. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 223. | FNA vol. 23, p. 233. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Phaeocephalum caducum, R. patula | R. fascicularis var. harperi, R. leptorhyncha |
Name authority | Elliott: Sketch Bot. S. Carolina 1: 62. (1816) | Small: Man. S.E. Fl., 182, 1503. (1933) |
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