Cyperus giganteus |
Cyperus fendlerianus |
|
---|---|---|
giant flatsedge, Mexican papyrus |
Fendler flatsedge, Fendler's flatsedge, Fendler's nutgrass, Fendler's sedge |
|
Habit | Herbs, perennial, rhizomatous, stout. | Herbs, perennial, rhizomatous. |
Culms | roundly trigonous, 200–350 cm × 15–50 mm, glabrous. |
trigonous, (7–)20–70(–85) cm × (0.5–)1–1.8(–2.6) mm, glabrous or sparsely to densely scabridulous on surfaces or on angles immediately proximal to inflorescence in distal 3–6 cm. |
Leaves | bladeless. |
2–3, flat to V-shaped, (12–)20–40(–55) cm × (2–)3–5(–7) 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. |
spikes (1–)3–4(–6), largest erect, others at base of central spike, erect spike sessile, loosely to densely cylindric to ovoid-cylindric, (12–)18–30 × (6–)12–20 mm, remaining spikes 1/2 as large; rays absent; bracts (2–)3–6(–10), ± horizontal to reflexed parallel to culm, (2–)6–16(–25) cm × (1.5–)2–4(–7) mm; rachilla ± deciduous, wingless. |
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. |
(8–)15–30, spreading to ascending-appressed, oblong-lanceoloid, quadrangular, slightly compressed, 5–8(–10) × (2–)2.4–3.4(–4.2) mm; floral scales (2–)4–6(–8), yellowish, reddish, or greenish brown, medially greenish, straight to excurved, laterally (2–)3–4(–5)-ribbed, medially (1–)3–(–5)-ribbed, ovate-orbiculate, 2.4–2.8(–3.4) × 2.4–2.8(–3.4) mm, apex obtuse, mucronate to cuspidate, stout, (0.1–)0.3–0.6 mm, 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 0.4–0.8 mm; styles 0.7–1.3 mm; stigmas 0.7–1.2 mm. |
Achenes | pale brown, sessile, oblong, 0.9–1 × 0.4–0.5 mm, apex scarcely apiculate, surfaces puncticulate. |
finely reticulate, brown to reddish brown, ± stipelike, obovoid, 1.6–1.9 × 1.1–1.4(–1.6) mm, base attenuate to cuneate, 0.1–0.2 × 0.2 mm, apex obtuse, apiculate, surfaces glabrous. |
Cyperus giganteus |
Cyperus fendlerianus |
|
Phenology | Fruiting summer. | Fruiting summer. |
Habitat | Stream banks, marshes | Clearings in montane forests |
Elevation | 0–10 m (0–0 ft) | 500–1800 m (1600–5900 ft) |
Distribution |
LA; TX; Mexico; Central America; South America; West Indies [Introduced in North America] |
AZ; CO; NM; TX; WY; Mexico
|
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.) |
Hybridization between Cyperus fendlerianus and C. sphaerolepis occurs occasionally in the southwestern United States and northern Mexico (B. G. Marcks 1972). The unnamed hybrid appears to be fully fertile and can be recognized by morphologic intermediacy. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 173. | FNA vol. 23, p. 177. |
Parent taxa | Cyperaceae > Cyperus > subg. Cyperus | Cyperaceae > Cyperus > subg. Cyperus |
Sibling taxa | ||
Synonyms | Chlorocyperus fendlerianus | |
Name authority | Vahl: Enum. Pl. 2: 364. (1805) | Boeckeler: Linnaea 35: 520. (1868) |
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