Rhynchospora debilis

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Plants perennial, cespitose, 20–45 cm; rhizomes absent. Culms erect to arching or spreading, leafy, ± filiform, ± terete, stiff to rather lax. Leaves exceeded by culm; blades linearfiliform, proximally shallowly concave, 1 mm, apex tapering, trigonous, blunt or broadly acute. Inflorescences: spikelet clusters 1–2, mostly compact, turbinate to hemispheric; leafy bracts setaceous, exceeding spikelet 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. Flowers: bristles 6 or vestigial, rarely reaching fruit midbody, 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, concavesided, 0.4–0.6 mm, sometimes apiculate.

Phenology: Fruiting late spring–fall.
Habitat: Sands and peats in low, open fields, bogs, seeps, low pinelands, savannas, and ditch banks
Elevation: 0–200 m

Ala., Fla., Ga., La., Miss., N.C., S.C., Tex., Va.

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.

Selected References

None.

Lower Taxa