Cyperus giganteus |
Cyperus lentiginosus |
|
---|---|---|
giant flatsedge, Mexican papyrus |
Latin American flatsedge |
|
Habit | Herbs, perennial, rhizomatous, stout. | Herbs, perennial, cespitose, rhizomatous. |
Culms | roundly trigonous, 200–350 cm × 15–50 mm, glabrous. |
trigonous, (1–) 20–40(–75) cm × 1–1.5(–2.5) mm, glabrous. |
Leaves | bladeless. |
inversely W-shaped, 10–40(–70) cm × (1–)3–6(–10) 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), broadly and loosely ovoid to oblong-ellipsoid, (15–)20–30(–50) × 20–30(–45) mm; bracts (3–)5–7(–10), ascending at 30(–45)°, inversely W-shaped, 10–30(–50) cm × (1–)3–5(–11) mm; rays (2–)3–6(–12), (1–)3–10(–17) cm; rachilla deciduous, wings ca. 0.3 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–)25–50(–100), ± terete, (appearing compressed due to excurved apices of floral scales), (8–)12–15(–24) × (0.8–)1.1–1.4(–1.8) mm; floral scales persistent, (4–)6–8(–14), golden brown, off-white to stramineous, densely red-glandular punctate, green medially, 3–4-ribbed laterally, 3–5-ribbed medially, oblong-lanceolate, (3.2–)4–4.5 × 1.2–1.6 mm, apex blunt, mucronulate to mucronate, mucro 0.2–0.5 mm; proximal scales mucronulate, distal scales mucronate; terminal scale conduplicate. |
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 0.5–0.8(–1.4) mm; styles 0.8–1 mm; stigmas 1–2 mm. |
Achenes | pale brown, sessile, oblong, 0.9–1 × 0.4–0.5 mm, apex scarcely apiculate, surfaces puncticulate. |
brown, ± sessile to stipitate, oblong-ellipsoid, 1.7–2 × 0.6–0.7 mm, 0.1(–0.2) × 0.2 mm, apex rounded, apiculate from dark purple style base, surfaces papillose. |
Cyperus giganteus |
Cyperus lentiginosus |
|
Phenology | Fruiting summer. | Fruiting spring–summer. |
Habitat | Stream banks, marshes | Thickets, open woods |
Elevation | 0–10 m (0–0 ft) | 0–50 m (0–200 ft) |
Distribution |
LA; TX; Mexico; Central America; South America; West Indies [Introduced in North America] |
FL; TX; Mexico; 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.) |
Cyperus lentiginosus has been treated as a variety of C. tenuis (G. Kükenthal 1935–1936). The two taxa differ in the longer scales with cuspidate apices of C. lentiginosus, the inversely W-shaped leaves and bracts (those of C. tenuis are V-shaped), and the open spikes (those of C. tenuis are dense). (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. strigosus var. gracilis, C. tenuis var. lentiginosus | |
Name authority | Vahl: Enum. Pl. 2: 364. (1805) | Millspaugh & Chase: Publ. Field Columbian Mus., Bot. Ser. 3: 74. (1903) |
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