Cyperus dentoniae

G. C. Tucker

Syst. Bot. Monogr. 2: 56. 1983.

Common names: Denton’s flatsedge
Illustrated
Basionym: Mariscus pubescens J. Presl & C. Presl 1828
Synonyms: Cyperus flavomariscus var. peduncularis Britton Cyperus flavus var. peduncularis (Britton) Kükenthal
Treatment appears in FNA Volume 23. Treatment on page 187. Mentioned on page 148, 185, 188.

Herbs, perennial, cespitose, shortly rhizomatous. Culms 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 2–5(–7), V-shaped, (5–)15–30(–45) cm × (1.5–)2.5–5(–8) mm. Inflorescences: 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 (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: anthers (0.3–)0.4–0.6 mm; styles 0.4–0.6(–0.8) mm; stigmas 1–1.4 mm. Achenes 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.


Phenology: Fruiting mid summer–fall (Jul–Sep).
Habitat: Various dry, open environments
Elevation: 500–1000 m

Distribution

V23 324-distribution-map.jpg

Ariz., Mexico, Central America, South America.

Discussion

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).

Selected References

None.

Lower Taxa

None.
... more about "Cyperus dentoniae"
Gordon C. Tucker* +, Brian G. Marcks* +  and J. Richard Carter * +
G. C. Tucker +
Mariscus pubescens +
Denton’s flatsedge +
Ariz. +, Mexico +, Central America +  and South America. +
500–1000 m +
Various dry, open environments +
Fruiting mid summer–fall (Jul–Sep). +
Syst. Bot. Monogr. +
Illustrated +
Cyperus flavomariscus var. peduncularis +  and Cyperus flavus var. peduncularis +
Cyperus dentoniae +
Cyperus subg. Cyperus +
species +