Cyperus giganteus |
Cyperus grayoides |
|
---|---|---|
giant flatsedge, Mexican papyrus |
Illinois flatsedge, Mohlenbrock's sedge, umbrella sedge |
|
Habit | Herbs, perennial, rhizomatous, stout. | Herbs, perennial, cespitose, rhizomatous, tuberlike. |
Culms | roundly trigonous, 200–350 cm × 15–50 mm, glabrous. |
trigonous, 5–35 cm × 0.7–1.2 mm, glabrous. |
Leaves | bladeless. |
V-shaped, 5–25 cm × 1.5–3.5 mm, slightly scabridulous on abaxial margins, midrib. |
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 loosely ± globose, 15–25 mm wide; rays 1–10 cm; rachis 1–4 mm; bracts 3–7, ascending, V-shaped, 3–20 cm × 1–3 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. |
3–24, compressed, oblong-lanceoloid, 4–12 × 2.5–3.2 mm; floral scales deciduous, 3–9, pale reddish brown, ovate, laterally 3–5-ribbed, 2.5–3 × 2–2.4 mm, apex acute to obtuse. |
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 1–1.2 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. |
dark brown, ± stipitate, ellipsoid, 2–2.4 × 0.9–1.2 mm, apex obtuse, apiculate, surfaces glabrous, puncticulate, or papillose. |
2n | = 166. |
|
Cyperus giganteus |
Cyperus grayoides |
|
Phenology | Fruiting summer. | Fruiting summer. |
Habitat | Stream banks, marshes | Sand prairies, waste places, fallow fields |
Elevation | 0–10 m (0–0 ft) | 100–300 m (300–1000 ft) |
Distribution |
LA; TX; Mexico; Central America; South America; West Indies [Introduced in North America] |
AR; IL; LA; MO; TX
|
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 grayoides is in the Center for Plant Conservation’s National Collection of Endangered Plant’s. See frontispiece. (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 | ||
Name authority | Vahl: Enum. Pl. 2: 364. (1805) | Mohlenbrock: Brittonia 11: 255, fig. 1. (1959) |
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