Cyperus schweinitzii |
Cyperus lentiginosus |
|
---|---|---|
sand flatsedge, Schweinitz's flatsedge |
Latin American flatsedge |
|
Habit | Herbs, perennial, rhizomatous. | Herbs, perennial, cespitose, rhizomatous. |
Culms | trigonous, (10–)20–50 cm × (0.6–)1–2 mm, glabrous or more often scabridulous, either in distal 1/2 or over entire length; basal sheaths, 1–3, light brown, 1–4 cm, papery. |
trigonous, (1–) 20–40(–75) cm × 1–1.5(–2.5) mm, glabrous. |
Leaves | flat to V-shaped, (2–)20–35 cm × 2–6 mm, margins and keel minutely scabridulous; proximal leaves bladeless. |
inversely W-shaped, 10–40(–70) cm × (1–)3–6(–10) mm. |
Inflorescences | spikes ± umbellate to slenderly (infrequently broadly) ovoid, 10–25 × 7–16 mm; rays 3–5, 1.5–8(–15) cm; bracts 3–7, erect (or declined at most 25–30° from vertical), (2.5–)8–20(–25) cm × (0.5–)1.5–6 mm; rachilla ± deciduous, wingless. |
spikes 1(–3), broadly and loosely ovoid to oblong-ellipsoid, (15–)20–30(–50) × 20–30(–45) mm; bracts (3–)5–7(–10), ascending at 30(–45)°, inversely W-shaped, 10–30(–50) cm × (1–)3–5(–11) mm; rays (2–)3–6(–12), (1–)3–10(–17) cm; rachilla deciduous, wings ca. 0.3 mm wide. |
Spikelets | (1–)5–10(–20), oblong to linear-oblong, quadrangular, 7–10(–18) × (2.8–)3.2–4(–4.5) mm; floral scales deciduous, (1–)5–10(–14), spreading, laterally stramineous or dull whitish, sometimes also red-spotted, medially green, laterally 2–3-ribbed, medially 3-ribbed, broadly ovate to oblong-ovate, (2.3–)2.8–3.2 × (2–)2.4–3.2 mm, apex broadly rounded, often clear-erose, cusp 0.1–0.4 mm in proximal scales, 0.3–1 mm in distal scales. |
(10–)25–50(–100), ± terete, (appearing compressed due to excurved apices of floral scales), (8–)12–15(–24) × (0.8–)1.1–1.4(–1.8) mm; floral scales persistent, (4–)6–8(–14), golden brown, off-white to stramineous, densely red-glandular punctate, green medially, 3–4-ribbed laterally, 3–5-ribbed medially, oblong-lanceolate, (3.2–)4–4.5 × 1.2–1.6 mm, apex blunt, mucronulate to mucronate, mucro 0.2–0.5 mm; proximal scales mucronulate, distal scales mucronate; terminal scale conduplicate. |
Flowers | anthers 0.8–1.4 mm; styles 0.1–0.3 mm; stigmas 1.5–3 mm. |
anthers 0.5–0.8(–1.4) mm; styles 0.8–1 mm; stigmas 1–2 mm. |
Achenes | light to dark brown or nearly black, broadly ellipsoid, infrequently obovoid, 2–2.4 × 0.9–1.4 mm, base cuneate to ± stipelike, apex obtuse to broadly rounded, surfaces papillose. |
brown, ± sessile to stipitate, oblong-ellipsoid, 1.7–2 × 0.6–0.7 mm, 0.1(–0.2) × 0.2 mm, apex rounded, apiculate from dark purple style base, surfaces papillose. |
2n | = 166. |
|
Cyperus schweinitzii |
Cyperus lentiginosus |
|
Phenology | Fruiting late spring–early summer. | Fruiting spring–summer. |
Habitat | Riverbanks, sand bars, lakeshores, sand dunes, sandy openings in woods | Thickets, open woods |
Elevation | 0–1000 m (0–3300 ft) | 0–50 m (0–200 ft) |
Distribution |
CO; IA; IL; KY; MA; MI; MN; MO; MT; NJ; NM; NY; OH; OK; PA; SD; TX; UT; WA; WI; WY; AB; MB; ON; QC; SK; Mexico (Coahuila)
|
FL; TX; Mexico; West Indies |
Discussion | Cyperus schweinitzii is introduced, but not naturalized, in Massachusetts and Washington. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Cyperus lentiginosus has been treated as a variety of C. tenuis (G. Kükenthal 1935–1936). The two taxa differ in the longer scales with cuspidate apices of C. lentiginosus, the inversely W-shaped leaves and bracts (those of C. tenuis are V-shaped), and the open spikes (those of C. tenuis are dense). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 174. | FNA vol. 23. |
Parent taxa | Cyperaceae > Cyperus > subg. Cyperus | Cyperaceae > Cyperus > subg. Cyperus |
Sibling taxa | ||
Synonyms | C. alterniflorus | C. strigosus var. gracilis, C. tenuis var. lentiginosus |
Name authority | Torrey: Ann. Lyceum Nat. Hist. New York 3: 276. (1836) | Millspaugh & Chase: Publ. Field Columbian Mus., Bot. Ser. 3: 74. (1903) |
Web links |