Cyperus hystricinus |
Cyperus distans |
|
---|---|---|
bristly flatsedge |
Piedmont flatsedge |
|
Habit | Herbs, perennial, cespitose, with well-developed rhizomes. | Herbs, perennial, rhizomatous. |
Culms | trigonous, 30–100 cm × 2–4 mm, basally cormlike, glabrous. |
single or close together, trigonous, (10–)40–80(–120) cm × 1.2–2.5(–5) mm, glabrous. |
Leaves | flat to broadly V-shaped, 20–70 cm × 4–6 mm, glabrous except for marginal prickles. |
2–5, pleated, (10–)20–50(–90) cm × 2–5(–10) mm. |
Inflorescences | spikes loosely to densely ovoid, oblong (2 times long as wide), 10–12 × 6–9 mm; rays 6–11, 1–16 cm, glabrous; bracts 5–10, ascending at 30–45°, flat, 6–25 cm × 3–6 mm; rachilla persistent, wings 0.5 mm wide, covering nearly entire length of achene. |
spikes 1–4(–7), loose, broadly ovoid to ovoid-pyramidal, 25–35 × 25–35 mm; rays (4–)5–6(–8), (1–)3–8(–16) cm, glabrous; 2d order rays (0–)1–5, 5–15(–50) mm; bracts 4–7, ascending at 30–45°, pleated, (5–)20–40(–60) × (2–)3–8(–11) mm; 2d order bracts 1–4 per ray, 5–10(–30) × 0.5–1 mm, scabridulous; rachilla persistent, wingless (or very narrowly winged, not clasping achene). |
Spikelets | (20–)40–100(–120), proximal spikelets reflexed somewhat, distal ones divaricate, ± terete, lanceoloid, 6–6.8 × 1–1.4 mm; floral scales persistent, 1–2(–3), appressed, golden brown, lanceolate, laterally 5–6-ribbed, 3.8–4.9 × 1.4–1.6 mm, apex mucronate, mucro at most 0.3 mm. |
(10–)20–35(–45), seemingly flattened proximally from spreading floral scales, becoming terete apically, linear, (10–)13–18(–25) × 1.2–1.5(–1.6) mm; floral scales deciduous, (10–)12–20(–25), laterally light reddish brown to dark red, medially greenish, laterally ribless, medially 3–5-ribbed, oblong-ovate, 1.7–2(–2.4) × 0.9–1.2 mm, apex obtuse, barely reaching next scale, apex entire, emarginate, mucro at most 0.3 mm. |
Flowers | anthers 1–1.3 mm; styles 0.8–1 mm; stigmas 2–3 mm. |
anthers 0.4–0.5 mm; styles 0.3–0.6 mm; stigmas 1–1.8(–2) mm. |
Achenes | brown, sessile, linear, 2.5–2.8 × 0.5–0.7 mm, apex obtuse, apiculate, surfaces muriculate. |
dark brown, narrowly oblong, (1.3–)1.4–1.6(–1.7) × (0.3–)0.4–0.5 mm, base cuneate to ± stipelike, apex acute, not apiculate, surfaces papillose. |
Cyperus hystricinus |
Cyperus distans |
|
Phenology | Fruiting late summer–early fall (Jul–Sep). | Fruiting summer. |
Habitat | Xeric, sandy soils of sand hills and pine barrens | Marshes |
Elevation | 0–200 m (0–700 ft) | 0 m (0 ft) |
Distribution |
AL; AR; DC; DE; GA; LA; MD; MO; MS; NC; NJ; TX; VA
|
FL; NC; Mexico; South America; West Indies (Dominican Republic south through the Lesser Antilles); Asia; Africa |
Discussion | Cyperus hystricinus resembles C. plukenetii and C. retrofractus; it can be readily distinguished from both by its glabrous culms. Overly mature specimens of C. lancastriensis are frequently misidentified as C. hystricinus; C. hystricinus may be confirmed by its narrow, nearly glabrous leaves and bracts, golden brown spikelets, longer, narrower achenes, and elongated rhizome internodes (to 15 mm vs. 5 mm in 76. C. lancastriensis). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 23. | FNA vol. 23. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | C. retrofractus var. hystricinus | C. elatus |
Name authority | Fernald: Rhodora 8: 127. (1906) | Linnaeus f.: Suppl. Pl., 103. (1782) |
Web links |