Cyperus prolixus |
Cyperus hypopitys |
|
---|---|---|
mosquito flatsedge |
pine flatsedge, pinewoods sedge |
|
Habit | Herbs, perennial; rhizomes 3–20 cm × 1–2 cm, indurate. | Herbs, perennial, rhizomatous, tending to form small clumps by basal offshoots. |
Culms | stoutly trigonous, thickened, 50–300 cm × 5–30 mm, basally indurate, glabrous. |
triquetrous, bulbous, thickened, (20–)30–80(–90) cm × 0.7–1.2 mm, glabrous proximally, becoming trigonous strongly scabridulous on distal angles, clothed with persistent reddish fibers at base. |
Leaves | V-shaped, with cross ribs, 40–130 cm × 10–15 mm, margins and keel scabrid. |
flat to V-shaped, 20–45 cm × 2–4 mm. |
Inflorescences | spikes appressed-ascending, narrowly cylindric, (2–)3–45 mm × (4–)7–10 mm; rays (5–)9–12, 2–22(–30) cm; 2d order rays distinctly flattened, 1–10 cm; 3d order rays flattened, 0.5–3 cm; rachis 2.5–4 cm; bracts (6–)9–10, ascending at 45–75°, V- or inversely W-shaped, (5–)15–90 cm × 0.5–20 mm; rachilla persistent, wings 0.2–0.4 mm wide. |
spike 1, loosely ovoid to ovoid-ellipsoid, (1.5–)2.5–7 × (1–)1.5–3.5 cm; rays (1–)2–4, to 6 cm; 2d order rays rarely present, to 2 cm; 3d order rays absent; bracts (2–) 3, ± horizontal, 1–15(–21) cm × 0.4–3.5 mm; rachilla deciduous, wings hyaline, 0.3–0.4 mm wide. |
Spikelets | (4–)10–35, appressed-ascending, compressed, linear, 7–12(–15) × 0.6–1.2 mm; floral scales deciduous, 6–20, marginally clear, laterally brown, medially green, laterally 2–3-ribbed, medially 1-ribbed, oblong-ovate, (3.2–) 3.8–4.3 × 1.2–1.7 mm, apex spreading, acute to obtuse, mucronulate. |
(3–)8–26, reddish to reddish brown, linear, compressed-quadrangular, 8–18 × (2.4–)2.8–4 mm; floral scales deciduous, 6–16, laterally reddish, medially green, occasionally red-glandular, laterally strongly 3(–4)-ribbed, medially punctate, 1–3-ribbed, ovate-lanceolate, (2.6–)2.8–3.3 × (1.4–)1.6–1.8(–2) mm, apex weakly 3-dentate, mucronulate, with tuft of crystalline prickles, medially glabrous. |
Flowers | anthers 0.7–0.9 mm, connective apex bright red, oblong, to 0.1 mm; styles 0.8–1.3 mm; stigmas 2–3.3 mm. |
anthers 0.8–1.1 mm; styles 1–1.4 mm; stigmas 1–1.4 mm. |
Achenes | brown, sessile, narrowly ellipsoid, 1.8–2.5 × 0.8–1.3 mm, apex ± acute, not apiculate, surfaces puncticulate. |
brownish, stipitate, ellipsoid, 1.6–2 × (0.7–)0.9–1 mm, base whitish, stipe to 0.1–0.2 mm, apex obtuse, slightly apiculate, surfaces papillose. |
Cyperus prolixus |
Cyperus hypopitys |
|
Phenology | Fruiting summer. | Fruiting late summer–early fall. |
Habitat | Coastal marshes | Canyons in pine forests |
Elevation | 0–10 m [0–30 ft] | 500–1500 m [1600–4900 ft] |
Distribution |
LA; Mexico; Central America; South America |
AZ; Mexico (Chihuahua, Durango, Sinaloa, Sonora) |
Discussion | Cyperus prolixus produces large plants, similar in habit to C. giganteus and C. papyrus but easily distinguished by flattened rays. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. Cyperus hypopitys can be recognized by the combination of reddish floral scales and sharp-angled culms. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 167. | FNA vol. 23, p. 178. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | C. amplissimus | |
Name authority | Kunth: in A. von Humboldt et al., Nov. Gen. Sp. 1: 206. (1816) | G. C. Tucker: Syst. Bot. Monogr. 43: 129, fig. 54. (1994) |
Web links |