Rhynchospora debilis |
Rhynchospora fernaldii |
|
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savannah beaksedge |
Fernald's beaksedge |
|
Habit | Plants perennial, cespitose, 20–45 cm; rhizomes absent. | Plants perennial, cespitose, 15–50 cm; rhizomes absent. |
Culms | erect to arching or spreading, leafy, ± filiform, ± terete, stiff to rather lax. |
erect or ascending, slender, leafy proximal to middle, somewhat stiff. |
Leaves | exceeded by culm; blades linearfiliform, proximally shallowly concave, 1 mm, apex tapering, trigonous, blunt or broadly acute. |
overtopped by culm; blades ascending, ± filiform, proximally flat or slightly concave, to 1 mm wide, apex narrowing, trigonous, abruptly blunt. |
Inflorescences | spikelet clusters 1–2, mostly compact, turbinate to hemispheric; leafy bracts setaceous, exceeding spikelet clusters. |
spikelet clusters 1–2, if 2 then close together, dense, broadly turbinate to hemispheric or even globose; primary leafy bract setaceous, exceeding clusters. |
Spikelets | dark redbrown, ovoid, 2–3 mm, apex acute; fertile scales obovate, 1.5–1.7(–2) mm, apex broadly rounded or retuse, midrib excurrent as cusp or mucro to 0.5 mm. |
redbrown, ovoid, 2–2.5(–4) mm, apex acute; fertile scales broadly ovate, 1.5–1.9(–2) mm, apex acute to acuminate, midrib excurrent as awn to 0.5 mm. |
Flowers | bristles 6 or vestigial, rarely reaching fruit midbody, antrorsely barbellate. |
bristles 6, some reaching to apex of fruit body. |
Fruits | 1–2 per spikelet,1.7–2 mm; body brown with large pale center, lenticular, broadly obovoid to ± orbicular, 1.2–1.5 × 1.4–1.6 mm; tubercle flat, triangular, concave-sided, 0.4–0.6 mm, sometimes apiculate. |
2–3 per spikelet, 1–1.2(–1.4) mm; body dull dark brown with paler brown center, lenticular, broadly obovoid to broadly ellipsoid, 1 × 0.8 mm, margins narrow, flowing to tubercle; tubercle nearly equilaterally triangular, 0.2–0.3 mm. |
Rhynchospora debilis |
Rhynchospora fernaldii |
|
Phenology | Fruiting late spring–fall. | Fruiting summer–fall. |
Habitat | Sands and peats in low, open fields, bogs, seeps, low pinelands, savannas, and ditch banks | Sands and peats of low clearings in flatwoods, savannas, and bog edges |
Elevation | 0–200 m (0–700 ft) | 0–100 m (0–300 ft) |
Distribution |
AL; FL; GA; LA; MS; NC; SC; TX; VA |
AL; FL; GA; MS |
Discussion | Rhynchospora debilis is very similar to R. wrightiana except it has smaller spikelet clusters and more depressed fruit tubercles. It is a common invader of cutover and bulldozed low pineland where it assumes a lowspreading habit, its many culms radiating from the common center much like spokes in a wheel. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 23. | FNA vol. 23, p. 235. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | R. fascicularis var. debilis | R. fascicularis var. fernaldii |
Name authority | Gale: Rhodora 46: 194, plate 826, figs. 5A, B. (1944) | Gale: Rhodora 46: 182, plate 825, figs. 3A, B. (1944) |
Web links |