Cyperus giganteus |
Cyperus fuligineus |
|
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giant flatsedge, Mexican papyrus |
limestone flatsedge |
|
Habit | Herbs, perennial, rhizomatous, stout. | Herbs, perennial, cespitose, rhizomatous. |
Culms | roundly trigonous, 200–350 cm × 15–50 mm, glabrous. |
trigonous, 7–30 cm × 0.5–1 mm, glabrous. |
Leaves | bladeless. |
V-shaped to flat, 5–20 cm × 1–2.5 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 hemispheric, 7–20 mm wide; rays absent; rachis 1–3 mm; bracts 2–3, reflexed, flat, 5–12 cm × 1–2 mm; rachilla deciduous, wings 0.2 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. |
30–50, compressed, oblong-lanceoloid, 4–10 × 1.7–2.3 mm; floral scales deciduous, 5–12, dark reddish brown, laterally 3–5-ribbed, ovate, 1.5–2.2 × 1–1.6 mm, apex with mucro 0.1–0.2 mm. |
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 0.4–0.6 mm; styles 0.4–0.6 mm; stigmas 1–2 mm. |
Achenes | pale brown, sessile, oblong, 0.9–1 × 0.4–0.5 mm, apex scarcely apiculate, surfaces puncticulate. |
black, sessile, narrowly ellipsoid, 1–1.2 × 0.5–0.6 mm, apex obtuse, apiculate, glabrous, puncticulate, or papillose. |
Cyperus giganteus |
Cyperus fuligineus |
|
Phenology | Fruiting summer. | Fruiting spring–summer. |
Habitat | Stream banks, marshes | Coastal rocks, exposed limestone in hammocks and edges of mangrove swamps |
Elevation | 0–10 m (0–0 ft) | 0–10 m (0–0 ft) |
Distribution |
LA; TX; Mexico; Central America; South America; West Indies [Introduced in North America] |
FL; West Indies |
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.) |
|
Source | FNA vol. 23, p. 173. | FNA vol. 23, p. 175. |
Parent taxa | Cyperaceae > Cyperus > subg. Cyperus | Cyperaceae > Cyperus > subg. Cyperus |
Sibling taxa | ||
Name authority | Vahl: Enum. Pl. 2: 364. (1805) | Chapman: Fl. South. U.S., 511. (1860) |
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