Rhynchospora compressa |
Rhynchospora pusilla |
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flatfruit beaksedge |
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Habit | Plants perennial, cespitose, 70–100(–150) cm; rhizomes absent. | Plants perennial, densely cespitose, 15–50(–60) cm; rhizomes absent. |
Culms | erect to ascending, leafiest at base, triangular, slender, somewhat stiff. |
erect or arching, leafy toward base, filiform, terete, wiry. |
Leaves | exceeded by culm; basal blades crowded, spreadingexcurved, distal ascending, linear, proximally flat, 3–5 mm wide, apex trigonous, shortsubulate. |
overtopped by culm; blades linear to filiform, channeled, 0.3–0.5 mm wide, margins deeply involute, apex setaceous. |
Inflorescences | spikelet clusters 3–5, compact, the proximalmost widely spaced, turbinate or lobed to hemispheric; leafy bracts setaceous, mostly overtopping clusters. |
spikelet clusters 1–2(–3), dense to open, narrowly to broadly turbinate; branches capillary, variously elongate; leafy bracts setaceous, equaling or exceeding clusters. |
Spikelets | redbrown, broadly ovoid, 3–3.5(–4) mm, apex acuminate; fertile scales broadly ovate to ± orbiculate, 2–2.5(–3) mm, apex rounded to notched, midrib included or shortexcurrent. |
variously brown, ellipsoid, 2–3 mm, apex sharply acute; fertile scales ovate to nearly orbiculate, rounded, 1.2–1.8 mm, apiculate, convexcupulate, midrib slender, mostly included. |
Flowers | perianth bristles 6, reaching from fruit midbody to tubercle, antrorsely barbellate. |
perianth absent. |
Fruits | 1–2 per spikelet, (2–)2.5–2.8(–3) mm; body brownish, broadly obovoid to nearly orbicular, 1.5–2 × 1.5–2 mm; surfaces strongly transversely wavyrugose, intervals rows of vertical, rectangular alveolae; tubercle conic-subulate, basal rim flaring above short neck on achene. |
2–3 per spikelet, 0.7–0.9(–1) mm; body pale, obovoid-lenticular, (0.5–)0.6–0.9 × 0.4–0.5 mm, margin wirelike; surfaces transversely rugulose; tubercle buttonlike, depressed triangular, 0.05–0.1 mm, base lunate atop rounded fruit body. |
Rhynchospora compressa |
Rhynchospora pusilla |
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Phenology | Fruiting spring–fall. | Fruiting summer–fall. |
Habitat | Moist sands and peats of pine flatwoods, bog margins, savannas | Moist sands, peats and silts of low meadows, savannas, bogs, seeps, pond shores |
Elevation | 0–100 m (0–300 ft) | 0–300 m (0–1000 ft) |
Distribution |
AL; FL; GA; LA; MS; SC |
AL; FL; GA; LA; MS; NC; SC; TX; Mexico; Central America; West Indies |
Discussion | Rhynchospora compressa is very closely akin to R. recognita and even coarser; inflorescence clusters are about as bristly and fertile scales blunter than those in R. recognita. It is less inclined to have an excurrent midrib, and the fruit is flatter. Both species often produce sterile spikelets, sometimes comprising an entire inflorescence. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 23. | FNA vol. 23, p. 220. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Phaeocephalum compressum, R. cymosa var. compressa | Phaeocephalum pusillum, R. intermixta |
Name authority | J. Carey ex Chapman: Fl. South. U.S., 525. (1860) | Chapman ex M. A. Curtis: Amer. J. Sci. Arts, ser. 2, 7: 409. (1849) |
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