Cyperus floribundus |
Cyperus owanii |
|
---|---|---|
Rio Grande sedge |
Owan's flatsedge |
|
Habit | Herbs, perennial, cespitose, rhizomatous. | Herbs, perennial, cespitose, rhizomatous. |
Culms | trigonous, basally tuberous thickened, 15–40 cm × 1–2.5 mm, glabrous. |
roundly trigonous, 80–120 cm × 3–6 mm, glabrous. |
Leaves | flat to V-shaped, 10–30 cm × 1–2 mm. |
5–12, V-shaped, 30–75 cm × 8–14 mm, septate, leathery, margins harshly scabrid. |
Inflorescences | spike 1, densely oblong to ellipsoid, 8–36 × 8–20 mm; rays 4–12, 10–20 cm; bracts 3–6, horizontal to ascending at 30°, V-shaped, 3–15 cm × (3–)4–5.8 mm; rachilla deciduous, wings 0.5–0.7 mm wide. |
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 | (5–)20–35(–60), linear to oblong, quadrangular; 4–12(–21) × 0.7–1.2 mm, base narrowed to 0.4–1 mm; floral scales persistent, 1–3(–5), appressed, laterally whitish to reddish brown, stramineous with reddish spots, medially green, laterally 3–6-ribbed (midrib distinctly scabrid at 30X), narrowly oblong to ovate, 2.6–4.8 × 1.6–2 mm; apex rounded to ± acute, entire, with mucro 0.3–0.5 mm; sterile terminal scale involute, 0.4–0.6 mm wide, uncinate; distal floral scales with cusp 0.6–1.9. |
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 0.5–1.3 mm; styles 0.4–0.5 mm; stigmas 0.5–0.9 mm. |
anthers (0.7–)1–1.5 mm, filaments 4–4.7 mm; styles 0.5–0.9 mm; stigmas 2–3 mm. |
Achenes | light brown to reddish brown, sessile to slightly stipitate, narrowly ellipsoid, 1.8–2.4 × 0.6–0.8 mm, apex slightly apiculate, surfaces puncticulate. |
brown, ellipsoid to oblong-fusiform, 1.7–1.8 × 0.7 mm, base cuneate, apex subacute and apiculate, surfaces finely puncticulate to glabrous. |
Cyperus floribundus |
Cyperus owanii |
|
Phenology | Fruiting mid summer–early fall (Jul–Sep). | Fruiting spring–fall. |
Habitat | Damp, disturbed soils, croplands | Disturbed, damp thickets, open woods |
Elevation | 0–1000 m (0–3300 ft) | 0–200 m (0–700 ft) |
Distribution |
TX; Mexico |
CA; s Africa [Introduced in North America] |
Discussion | Included previously in Cyperus retroflexus (or its synonym C. uniflorus), C. floribundus has a much narrower geographic range (southern Texas and northeastern Mexico) and differs in features of spikelet morphology (J. R. Carter and S. D. Jones 1997). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23. | FNA vol. 23, p. 184. |
Parent taxa | Cyperaceae > Cyperus > subg. Cyperus | Cyperaceae > Cyperus > subg. Cyperus |
Sibling taxa | ||
Synonyms | C. uniflorus var. floribundus, C. uniflorus | Mariscus umbilensis |
Name authority | (Kükenthal) J. Rich. Carter & S. D. Jones: Rhodora 99: 330. (1998) | Boeckeler: Flora 61: 29. (1878) |
Web links |