Rhynchospora harveyi |
Rhynchospora thornei |
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Harvey's beaksedge |
Thorne's beaksedge |
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Habit | Plants perennial, cespitose, 70–110 cm; rhizomes absent. | Plants perennial, densely cespitose, 10–20 cm; rhizomes slender, short. | ||||
Culms | erect to excurved, leafy, obscurely trigonous, slender. |
lax, filiform, leafy. |
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Leaves | spreading to ascending, shorter than culm, crowded toward culm base; blades linear, proximally flat, 1–3 mm wide, gradually involute, apically trigonous, subulate. |
spreading to ascending, exceeding or exceeded by culm; blades 0.2–0.3 mm wide, margins strongly involute or channeled, apex trigonous, tapering, setaceous. |
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Inflorescences | spikelet clusters 1–4, dense to open, mostly irregularly turbinate; peduncles ascending, branches spreading to erect, ultimate branches with many spikelets; leafy bracts setaceoustipped, usually exceeding all clusters, or at least all but the distal. |
cluster of cymes 1–2, widely spaced, turbinate, sparse; branches few; foliaceous bracts setaceous, longer than cymes. |
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Spikelets | light redbrown or brown, broadly ellipsoid to lanceoloid, 3–4 mm, apex acute to acuminate; fertile scales ovate to obovate or suborbiculate, 2–3.5 mm apex acute to rounded or emarginate, midrib included or exserted as mucro. |
brown, lanceovoid to fusiform, 2.5–3 mm, apex acuminate; fertile scales ovate, 1.5 mm, apex acute, midrib shortexcurrent. |
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Flowers | perianth bristles mostly 6, rarely reaching fruit midbody, antrorsely barbellate. |
perianth absent. |
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Fruits | mostly 1 per spikelet, 2–2.5 mm, body dark brown, obovoid to subglobose, tumid or lenticular, 1.5–1.7 mm, transversely finely rugose to nearly level, intervals with very small, pitlike alveoli. |
0.9–1 mm; body lustrous pale brown, ellipsoidlenticular, 0.8–0.9 × 0.5–0.6 mm, margins narrow, wirelike; surfaces minutely reticulate; bristles 4–6, the longest from shorter than fruit midbody to fully as long, rarely reaching tubercle tip, minutely antrorsely barbellate; tubercle shortconic, to 0.15 mm. |
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Rhynchospora harveyi |
Rhynchospora thornei |
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Phenology | Fruiting late spring summer. | |||||
Habitat | Fluctuating shores of limesink ponds, seeps over calcareous rock | |||||
Elevation | 0–200 m (0–700 ft) | |||||
Distribution |
AL; AR; FL; GA; KS; LA; MO; MS; NC; OK; SC; TN; TX; VA; se United States; Midwestern |
AL; FL; GA; NC |
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Discussion | Varieties 2 (2 in the flora). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. Rhynchospora thornei, discovered by Robert Thorne from margins of a limesink pond in southwestern Georgia, has been extirpated at that site. Now the taxon is known from several Alabama and Florida locations and was recently found in eastern North Carolina by R. J. LeBlond. Had S. Gale been sent material of Rhynchospora thornei at the time she was doing her excellent revision, she probably would have treated it as part of her series Rariflorae. Yet without its perianth bristles, R. thornei would be nearly identical to R. divergens and very similar to R. pusilla, both of which belong in subg. Psilocarya. Therefore, it forms an interesting link between subg. Rhynchospora (Eurhynchospora sensu Gale) and subg. Psilocarya. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 23, p. 231. | FNA vol. 23, p. 221. | ||||
Parent taxa | Cyperaceae > Rhynchospora | Cyperaceae > Rhynchospora | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Name authority | W. Boott: Bot. Gaz. 9: 85. (1884) | Kral: Sida 7: 42, fig. 1. (1977) | ||||
Web links |