Rhynchospora debilis |
Rhynchospora indianolensis |
|
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savannah beaksedge |
indianola beaksedge |
|
Habit | Plants perennial, cespitose, 20–45 cm; rhizomes absent. | Plants perennial, cespitose, to 100 cm; rhizomes absent. |
Culms | erect to arching or spreading, leafy, ± filiform, ± terete, stiff to rather lax. |
stiffly erect or ascending, leafy-based, triangular, multiribbed. |
Leaves | exceeded by culm; blades linearfiliform, proximally shallowly concave, 1 mm, apex tapering, trigonous, blunt or broadly acute. |
ascending or erect, crowded toward culm base, shorter, more widely spaced distally, longest overtopping or equaling subtended inflorescences; principal blades flat, trigonous distally, 4–6 mm wide, apex attenuate, trigonous. |
Inflorescences | spikelet clusters 1–2, mostly compact, turbinate to hemispheric; leafy bracts setaceous, exceeding spikelet clusters. |
terminal and axillary, compounds of fascicles, nearly umbellate; clusters hemispheric to nearly capitate, 1.5–2 cm wide; 1 cluster nearly sessile, others on slender rays to 7 cm, sometimes penultimate node with single cluster on peduncle 7–12 cm. |
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. |
light redbrown, lanceoloid, 6–7 mm, apex acute; fertile scales lance-ovate, 5 mm, apex acute to blunt, midrib shortexcurrent or not. |
Flowers | bristles 6 or vestigial, rarely reaching fruit midbody, antrorsely barbellate. |
perianth bristles 6, overtopping tubercle base, antrorsely barbellate. |
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. |
1 per spikelet, (5.5–)6–7 mm; body obovoid, 3–4 × 2–2.5 mm, margins thick, crimped, surfaces level or concave, minutely pebbled; tubercle narrowly conic, 2grooved, 3–4 mm, base blunt, stout, capping fruit apex, tip barely exserted. |
Rhynchospora debilis |
Rhynchospora indianolensis |
|
Phenology | Fruiting late spring–fall. | Fruiting early summer–fall. |
Habitat | Sands and peats in low, open fields, bogs, seeps, low pinelands, savannas, and ditch banks | Silty shallows of pools, prairie swales, ditches |
Elevation | 0–200 m (0–700 ft) | 0–100 m (0–300 ft) |
Distribution |
AL; FL; GA; LA; MS; NC; SC; TX; VA |
TX |
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.) |
Rhynchospora indianolensis was considered by G. Kükenthal to be closely related to, if not the same as, the Cuban R. scutellata Grisebach but with fruit of different dimensions and sculpture. W. W. Thomas (1984) believed the two to be conspecific. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23. | FNA vol. 23, p. 207. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | R. fascicularis var. debilis | |
Name authority | Gale: Rhodora 46: 194, plate 826, figs. 5A, B. (1944) | Small: Fl. S.E. U.S., 193, 1327. (1903) |
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