Rhynchospora harperi |
Rhynchospora perplexa |
|
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Harper's beaksedge |
pineland beaksedge |
|
Habit | Plants perennial, solitary or cespitose, 50–70 cm; rhizomes absent. | Plants perennial, cespitose, 50–110 cm; rhizomes absent. |
Culms | erect to excurved, leafybased, narrowly linear, ± terete. |
lax, often excurved, slender, ± terete or trigonous. |
Leaves | 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. |
ascending, exceeded by culm; blades linear, proximally flat, 1.5–2.5 mm wide, apex trigonous, subulate, tapering. |
Inflorescences | spikelet clusters 1–3, laterals 0–2, all turbinate to hemispheric, terminal internode usually excurved; leafy bracts setaceous, overtopping inflorescence. |
clusters 3–4, widely spaced, narrowly, compactly, or diffusely turbinate; leafy bracts exceeding proximal clusters. |
Spikelets | 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. |
deep redbrown, ovoid to broadly ellipsoid, 2–3 mm, apex acute to acuminate; fertile scales broadly elliptic to obovate or orbiculate, 1.4–2(–2.5) mm, apex rounded to notched, midrib shortexcurrent. |
Flowers | bristles 6, reaching from mid tubercle to beyond tip. |
perianth bristles 0–3, vestigial when present. |
Fruits | 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. |
2–4 per spikelet, 1.5 mm; body pale brown to brown, strongly flattened, orbicular to broadly obovoid, 1–1.3 × 0.9–1.2 mm, surfaces sharply transversely wavyrugose, intervals finely vertically striate with rows of linearrectangular alveolae; tubercle depressed, triangular, flattened, 0.2–0.3 mm, base lunate. |
Rhynchospora harperi |
Rhynchospora perplexa |
|
Phenology | Fruiting summer–fall. | Fruiting late spring–fall or all year (south). |
Habitat | Sands and peats of bogs, stream banks, edges of pineland savanna ponds, Hypericum ponds | Sands and peats of pond and lakeshores, depressions in savannas and flatwoods, or seeps |
Elevation | 0–100 m (0–300 ft) | 0–400 m (0–1300 ft) |
Distribution |
AL; DE; FL; GA; MD; MS; NC; SC; Central America (Belize)
|
AL; FL; GA; LA; MS; NC; SC; TN; TX; VA; Central America; West Indies (Cuba, Dominican Republic) |
Discussion | 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.) |
In habit and in shape, size, and color of spikelet, Rhynchospora perplexa strongly resembles R. microcarpa, a species with which it is commonly associated in the Coastal Plain. An examination of the fruit shows those of R. perplexa to be flattened, with fewer and much coarser transverse ridges, the intervals with very narrow vertical alveolae. The perianth in most instances is absent or rudimentary. Fruit of R. microcarpa is biconvex with more transverse ridges (eight or more), the intervals more coarsely alveolate; its perianth bristles are six, evident, extending at least halfway up the fruit body. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 233. | FNA vol. 23, p. 229. |
Parent taxa | Cyperaceae > Rhynchospora | Cyperaceae > Rhynchospora |
Sibling taxa | ||
Synonyms | R. fascicularis var. harperi, R. leptorhyncha | Phaeocephalum perplexum |
Name authority | Small: Man. S.E. Fl., 182, 1503. (1933) | Britton: in J. K. Small, Fl. S.E. U.S., 197, 1328. (1903) |
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