Cyperus retrorsus |
Cyperus distinctus |
|
---|---|---|
pine barren flatsedge |
swamp flatsedge |
|
Habit | Herbs, perennial, cespitose, shortly rhizomatous. | Herbs, perennial, cespitose, rhizomatous. |
Culms | trigonous, 20–50(–85) cm × 1–2(–4) mm, glabrous. |
terete, 40–60(–90)cm, glabrous. |
Leaves | 3–6(–10), 10–40(–55) cm × 1.5–4(–5) mm, V- to inversely W-shaped. |
flat, 35–70 cm × 4–9(–12) mm. |
Inflorescence(s) | spike 1, densely oblong-ovoid often with small basal branches, 8–16 × 4–12(–16) mm; rays 4–8(–11), 0.5–3.5(–8.5) cm; bracts (3–)4–6(–10), ascending at (30–)45°, flat to broadly V-shaped, (4–)14–30(–55) cm × 1–5 mm, scabridulous along margins only; rachilla deciduous, wings persistent, 0.2–0.3 mm wide. |
heads hemispheric, 10–20 mm diam.; rays 5–9(–14), 3.5–10 cm; 2d order rays 0.5–2 cm; bracts 5–10, ± horizontal, flat, 12–40(–50) cm × 2–7 mm. |
Spikelets | 40–120, oblong-lanceoloid, subterete, 2.2–4(–4.5) × 0.8–1.6 mm; distal spikelet spreading or ascending; floral scales persistent, 2–5, appressed, brown to stramineous, or fuscous and lustrous, medially greenish and 1(–3)-ribbed, laterally greenish to yellowish white and 3–4-ribbed, oblong to oblong-lanceolate, 1.8–2.5 × 1–1.5 mm, subcoriacous. |
(25–)35–50(–60), ovoid, compressed, (3.5–)5–12(–14) × 2.5–3.5(–4) mm; floral scales 10–32, golden brown to brown, 2-keeled, laterally ribless, narrowly lanceolate, 2–2.2(–3) × 0.8–1.4 mm. |
Flowers | anthers 0.3–0.5 mm; styles 0.5–0.8 mm; stigmas 0.6–0.9 mm. |
stamen 1; anthers 1 mm; styles 1 mm; stigmas 0.5 mm. |
Achenes | brown, oblong-ellipsoid, 1.2–1.7 × 0.5–0.6 mm, base cuneate, apex subacute, surfaces papillose. |
brown, stipitate, narrowly ellipsoid, 1.5–2 × 0.2–0.4 mm, base swollen, spongy, stipe 0.2 × 0.2–0.3 mm, apex acute, beak slender, 0.2 mm, surfaces puncticulate. |
Cyperus retrorsus |
Cyperus distinctus |
|
Phenology | Fruiting summer (Jun–Aug). | Fruiting summer. |
Habitat | Open woods and thickets in moist to dry, sandy soils | Damp grasslands, roadsides, ditches |
Elevation | 0–1000 m (0–3300 ft) | 0–50 m (0–200 ft) |
Distribution |
AL; AR; DC; DE; FL; GA; LA; MD; MO; MS; NC; NJ; NY; OK; SC; TN; TX; VA; Mexico (Tamaulipas)
|
FL; GA; LA; SC; West Indies (Bahamas) |
Discussion | Cyperus retrorsus was reported in Indiana (M. L. Horvat 1941); we have been unable to confirm the report. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
The slender achenes with conspicuously swollen bases distinguish Cyperus distinctus from other species of subg. Pycnostachys. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 187. | FNA vol. 23, p. 154. |
Parent taxa | Cyperaceae > Cyperus > subg. Cyperus | Cyperaceae > Cyperus > subg. Pycnostachys |
Sibling taxa | ||
Synonyms | Mariscus cylindricus, C. cylindricus, Mariscus retrorsus | C. virens var. brittonii |
Name authority | Chapman: Bot. Gaz. 3: 17. (1878) | Steudel: Syn. Pl. Glumac. 2: 24. (1855) |
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