Owan's Flat Sedge

Cyperus owanii is easily distinguished from other sedges in California by the large size, reddish spikelets, and secondary rays. It was first collected in California in 1938.

Herbs, perennial, cespitose, rhizomatous. Culms roundly tri-gonous, 80–120 cm × 3–6 mm, glabrous. Leaves 5–12, V-shaped, 30–75 cm × 8–14 mm, septate, leathery, margins harshly scabrid. Inflorescences: spikes 1–4 per ray, loosely ovoid to broadly ellipsoid, 12–20 × 8–12 mm; rays 6–9, 3–10(–12) cm; 2d order rays 1–4, 1–2 cm; rachis 4–12 mm; bracts 5–10, horizontal to ascending at 30°, 15–40 cm × 4–8(–11) mm; rachilla deciduous, wings persistent, hyaline, fragile, 0.3 mm wide, covering less than 1/2 of achene. Spikelets 40–80, narrowly ellipsoid to ellipsoid, roughly quadrangular to weakly flattened, 5–8 × 1.2–1.5 mm; distal spikelet spreading or ascending; floral scales (1–)2(–3), ascending, brick red, medially greenish, laterally 3–4-ribbed, medially 1–3-ribbed, green, ovate, 2.2–3.5 × 1.5–1.8 mm, apex subacute. Flowers: anthers (0.7–)1–1.5 mm, filaments 4–4.7 mm; styles 0.5–0.9 mm; stigmas 2–3 mm. Achenes brown, ellipsoid to oblong-fusiform, 1.7–1.8 × 0.7 mm, base cuneate, apex subacute and apiculate, surfaces finely puncticulate to glabrous.

introduced; Calif.; s Africa.

Fruiting spring–fall.

Disturbed, damp thickets, open woods; 0–200m.

Mariscus umbilensis (Kuntze) C. B. Clarke ex S. Watson

Cyperus owanii is a species of sedge that is native to parts of south eastern Africa.

The species was first formally described by the botanist Johann Otto Boeckeler in 1878.