Cyperus giganteus |
Cyperus pallidicolor |
|
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giant flatsedge, Mexican papyrus |
pallid flatsedge |
|
Habit | Herbs, perennial, rhizomatous, stout. | Herbs, perennial, cespitose, rhizomatous. |
Culms | roundly trigonous, 200–350 cm × 15–50 mm, glabrous. |
trigonous, (10–) 30–50(–80) cm × (0.8–)1–2 mm, glabrous or occasionally minutely scabridulous on distal angles. |
Leaves | bladeless. |
3–7, M- or V-shaped, (10–)25–40(–55) cm × 2–5 mm, margins and midribs scabridulous or glabrous. |
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 3–6(–12), grayish to golden brown, loosely cylindric, (6–)10–20(–24) cm × (5–)8–11 mm; rays 0 or 1–3, to 4 cm; rachis glabrous; bracts (3–)4–6(–8), horizontal to strongly reflexed, inversely W-shaped, (3–) 10–20(–30) cm × 1–5 mm; rachilla deciduous, wings persistent, 0.3–0.5 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. |
(10–)25–60(–100), spaced 1–2(–3) mm apart, broadly ellipsoid to oblong, ± terete, 2.4–3.6 × 0.8–1.2 mm; distal spikelet spreading or ascending; floral scales persistent, 1–2(–4), appressed, laterally golden brown to dull grayish white, frequently streaked with red, medially greenish, laterally 3–4-ribbed, medially 3-ribbed, oblong, 2.6–3.3 × 1.8–2.4 mm, apex broadly rounded. |
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 0.6–0.8 mm; styles 0.8–1.2(–1.4) mm; stigmas 1.4–2 mm. |
Achenes | pale brown, sessile, oblong, 0.9–1 × 0.4–0.5 mm, apex scarcely apiculate, surfaces puncticulate. |
reddish brown to dark brown, stipitate, ellipsoid, (1.6–)1.8–2(–2.2) × (0.6–)0.7–0.9 mm, base cuneate to ± attenuate, apex ± acute to broadly rounded, surfaces finely papillose to essentially glabrous. |
Cyperus giganteus |
Cyperus pallidicolor |
|
Phenology | Fruiting summer. | Fruiting summer. |
Habitat | Stream banks, marshes | Clearings in montane forests |
Elevation | 0–10 m (0–0 ft) | 800–1200 m (2600–3900 ft) |
Distribution |
LA; TX; Mexico; Central America; South America; West Indies [Introduced in North America] |
AZ; NM; Mexico; Central America; South America |
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. |
Parent taxa | Cyperaceae > Cyperus > subg. Cyperus | Cyperaceae > Cyperus > subg. Cyperus |
Sibling taxa | ||
Synonyms | C. subambiguus var. pallidicolor | |
Name authority | Vahl: Enum. Pl. 2: 364. (1805) | (Kükenthal) G. C. Tucker: in R. McVaugh & W. R. Anderson, Fl. Novo-Galiciana 13: 324. (1993) |
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