Cyperus giganteus |
Cyperus hypopitys |
|
---|---|---|
giant flatsedge, Mexican papyrus |
pine flatsedge, pinewoods sedge |
|
Habit | Herbs, perennial, rhizomatous, stout. | Herbs, perennial, rhizomatous, tending to form small clumps by basal offshoots. |
Culms | roundly trigonous, 200–350 cm × 15–50 mm, 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 | bladeless. |
flat to V-shaped, 20–45 cm × 2–4 mm. |
Inflorescences | spikes loosely cylindric, 15–40 × 8–16 mm; rays 5–8, ascending to erect, stiff,20–30 cm; 2d order rays 5–15 cm; bracts 10–12, ascending at 30–60°, flat, (8–) 20–45 cm × 4–12 mm; 2d order bracts (5–)15–25 cm × 1.5–5 mm; rachilla persistent, separating laterally, remaining firmly attached basally, wings 0.3–0.4 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 | (15–)50–80, slightly compressed, linear, ± quadrangular, 5–12 × 0.6–1.4 mm; floral scales 8–20, appressed, reddish beside 5-ribbed green medial part, white to hyaline near margins, ovate, 1.8–2.2 × 1.2–1.5 mm, apex acute to obtuse. |
(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 0.7–1 mm (connective prolonged beyond anther as red subulate appendage 0.2–0.5 mm, its apex sometimes setose); styles 0.2–0.5 mm; stigmas (0.8–)1.2–1.8 mm. |
anthers 0.8–1.1 mm; styles 1–1.4 mm; stigmas 1–1.4 mm. |
Achenes | pale brown, sessile, oblong, 0.9–1 × 0.4–0.5 mm, apex scarcely 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 giganteus |
Cyperus hypopitys |
|
Phenology | Fruiting summer. | Fruiting late summer–early fall. |
Habitat | Stream banks, marshes | Canyons in pine forests |
Elevation | 0–10 m (0–0 ft) | 500–1500 m (1600–4900 ft) |
Distribution |
LA; TX; Mexico; Central America; South America; West Indies [Introduced in North America] |
AZ; Mexico (Chihuahua, Durango, Sinaloa, Sonora) |
Discussion | Cyperus giganteus was erroneously reported from Florida, a misidentification of C. papyrus (R. R. Haynes and A. Lasseigne 1969). Recently, some nurseries specializing in water plants have begun to offer C. giganteus under the name “Mexican papyrus.” Escaped cultivated plants may be expected in southeastern and southwestern United States. (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. 173. | FNA vol. 23, p. 178. |
Parent taxa | Cyperaceae > Cyperus > subg. Cyperus | Cyperaceae > Cyperus > subg. Cyperus |
Sibling taxa | ||
Name authority | Vahl: Enum. Pl. 2: 364. (1805) | G. C. Tucker: Syst. Bot. Monogr. 43: 129, fig. 54. (1994) |
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