Cyperus gracilis |
Cyperus dentoniae |
|
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slimjim flatsedge |
Denton's flatsedge, hairy flatsedge |
|
Habit | Herbs, annual or perennial. | Herbs, perennial, cespitose, shortly rhizomatous. |
Culms | weak, often arching, basally culmlike, weakly 4(–5)-angled, 10–30 cm × 0.2–0.4 mm, glabrous. |
1–4, trigonous, (2–)20–50(–80) cm × (0.8–)1.5–2(–2.8) mm, basally glabrous or nearly so, apically hispidulous, on faces and angles distally, especially so immediately proximal to bracts. |
Leaves | 1–4, 3–25 cm × 1–1.5 mm. |
2–5(–7), V-shaped, (5–)15–30(–45) cm × (1.5–)2.5–5(–8) mm. |
Inflorescences | rays absent, often proliferous; bracts 2–4, longest erect, looking like continuation of culm, V-shaped, 3–6 cm × 1–3 mm. |
spike 1 (occasionally 1–2 smaller sessile spikes at base), densely cylindric, (7–)11–20(–25) × (5–) 7–10(–12) mm; rays 3–6(–10), (1–)3–6(–18) cm, rays and rachis hispidulous; bracts 4–8(–10), ascending at 30–60°, V-shaped, (2–)10–25(–45) cm × (1–)3–6(–8) mm; rachilla deciduous, wings persistent, 0.3–0.4 mm wide. |
Spikelets | 1–3(–6), narrowly ellipsoid, weakly compressed, 5–10 × 2 mm; floral scales 8–16, laterally whitish or dull stramineous, medially green, weakly 3–4-ribbed, broadly ovate, 2.5 × 2 mm, apex acute to mucronate, mucro slightly excurved, 0.2–0.3 mm. |
(20–)70–120(–140), oblong-ellipsoid to oblong-lanceoloid, ± terete to quadrangular, (2.2–)3.4–4.5(–5.6) × (0.8–)0.9–1.2(–1.3) mm; distal spikelet spreading or ascending; floral scales 1(–3), appressed, stramineous, red-spotted, strongly 3(–4)-ribbed on either side of green part, medially weakly 3-ribbed, ovate to elliptic ovate, (2.4–)2.8–3.3(–3.6) × 1.6–2 mm, apex acute, mucronulate from excurrent midrib. |
Flowers | stamens 3; styles 0.8 mm; stigmas 1–1.3 mm. |
anthers (0.3–)0.4–0.6 mm; styles 0.4–0.6(–0.8) mm; stigmas 1–1.4 mm. |
Achenes | brown, stipitate, obovoid, abaxial angle more prominent than adaxial ones, 0.7 × 0.7 mm, apex emarginate, surfaces glabrous. |
brown, stipitate, ellipsoid, (1.6–)1.8–2 × (0.7–) 0.8–0.9 mm, stipe 0.1–0.2 × 0.2 mm, apex ± truncate, apiculate, surfaces puncticulate to glabrous. |
Cyperus gracilis |
Cyperus dentoniae |
|
Phenology | Fruiting summer–early fall. | Fruiting mid summer–fall (Jul–Sep). |
Habitat | Disturbed, moist areas | Various dry, open environments |
Elevation | 0–100 m (0–300 ft) | 500–1000 m (1600–3300 ft) |
Distribution |
CA; Australia [Introduced in North America] |
AZ; Mexico; Central America; South America |
Discussion | Carex gracilis comprises diminutive plants with a delicate, arching habit and distinctive knoblike angles to the achenes. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Cyperus dentoniae was not treated in G. Kükenthal’s monograph (1935–1936), apparently because he did not see any materials of the species. The plant has been treated as “C. asper (Liebmann) O’Neill,” a name based on Mariscus asper Liebmann and a synonym of C. mutisii (A. B. Ayers 1946). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23. | FNA vol. 23, p. 187. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Mariscus pubescens, C. flavomariscus var. peduncularis, C. flavus var. peduncularis | |
Name authority | R. Brown: Prodr., 213. (1810) | G. C. Tucker: Syst. Bot. Monogr. 2: 56. (1983) |
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