Rhynchospora harveyi |
Rhynchospora decurrens |
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Harvey's beaksedge |
swampforest beaksedge |
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Habit | Plants perennial, cespitose, 70–110 cm; rhizomes absent. | Plants perennial, cespitose, to 100 cm; rhizomes sometimes produced, short, not stoloniferous. | ||||
Culms | erect to excurved, leafy, obscurely trigonous, slender. |
lax, erect to ascending-excurved, ± terete, leafy, slender, soft. |
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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. |
exceeded by inflorescence; blades erect or ascending, linear, proximally flat, 2–4 mm wide, apex trigonous, subulate, tapering. |
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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. |
spikelet clusters 4–6, widely spaced, loose, broadly to narrowly turbinate, paniculate, branches capillary, ultimate branches with 1 or 2 spikelets; leafy bracts exceeding proximal clusters, setaceous. |
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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. |
solitary or in 2s, brown, ovoid, 2.5–3.5 mm; fertile scales ovate, 1.5–2.2 mm, apex acute, apiculate. |
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Flowers | perianth bristles mostly 6, rarely reaching fruit midbody, antrorsely barbellate. |
perianth bristles 6, reaching tubercle base or slightly beyond, antrorsely barbellate. |
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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. |
2–3 per spikelet, 1.5–1.6(–1.8) mm; body brown or greenish, obovoid, lenticular, 1.1–1.2(–1.3) × 0.7–1 mm, margins narrow, distinct, sharp, flowing to tubercle; surfaces finely transversely wavyrugulose, intervals of fine, nearly isodiametric or vertical-rectangular pitlike alveolae; tubercle lowtriangular, entire, 0.3–0.4 mm. |
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Rhynchospora harveyi |
Rhynchospora decurrens |
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Phenology | Fruiting late spring–summer. | |||||
Habitat | Sandy alluvium of swamp forests and environs | |||||
Elevation | 0–100 m (0–300 ft) | |||||
Distribution |
AL; AR; FL; GA; KS; LA; MO; MS; NC; OK; SC; TN; TX; VA; se United States; Midwestern |
AL; FL; GA; LA; MS; NC; SC |
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Discussion | Varieties 2 (2 in the flora). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Rhynchospora decurrens superficially resembles R. mixta, with which it is often associated in swamp forests. Its narrower fruit bodies with less distinct transverse rugosity; the smaller, more numerous rows of finer, pitlike alveolae; and its broader, lower tubercles with non-setose edges all comprise consistent differences. The name decurrens is apt, calling attention to the narrow, wirelike pale margins that extend from tubercle base to near the base of the fruit body. (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. 226. | ||||
Parent taxa | Cyperaceae > Rhynchospora | Cyperaceae > Rhynchospora | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | Phaeocephalum decurrens | |||||
Name authority | W. Boott: Bot. Gaz. 9: 85. (1884) | Chapman: Fl. South. U.S., 525. (1860) | ||||
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