Cyperus grayoides |
Cyperus giganteus |
|
---|---|---|
Illinois flatsedge, Mohlenbrock's sedge, umbrella sedge |
giant flatsedge, Mexican papyrus |
|
Habit | Herbs, perennial, cespitose, rhizomatous, tuberlike. | Herbs, perennial, rhizomatous, stout. |
Culms | trigonous, 5–35 cm × 0.7–1.2 mm, glabrous. |
roundly trigonous, 200–350 cm × 15–50 mm, glabrous. |
Leaves | V-shaped, 5–25 cm × 1.5–3.5 mm, slightly scabridulous on abaxial margins, midrib. |
bladeless. |
Inflorescences | 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. |
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. |
Spikelets | 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. |
(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. |
Flowers | anthers 1–1.2 mm; styles 0.4–0.6 mm; stigmas 1–2 mm. |
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. |
Achenes | dark brown, ± stipitate, ellipsoid, 2–2.4 × 0.9–1.2 mm, apex obtuse, apiculate, surfaces glabrous, puncticulate, or papillose. |
pale brown, sessile, oblong, 0.9–1 × 0.4–0.5 mm, apex scarcely apiculate, surfaces puncticulate. |
2n | = 166. |
|
Cyperus grayoides |
Cyperus giganteus |
|
Phenology | Fruiting summer. | Fruiting summer. |
Habitat | Sand prairies, waste places, fallow fields | Stream banks, marshes |
Elevation | 100–300 m (300–1000 ft) | 0–10 m (0–0 ft) |
Distribution |
AR; IL; LA; MO; TX
|
LA; TX; Mexico; Central America; South America; West Indies [Introduced in North America] |
Discussion | 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.) |
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. | FNA vol. 23, p. 173. |
Parent taxa | Cyperaceae > Cyperus > subg. Cyperus | Cyperaceae > Cyperus > subg. Cyperus |
Sibling taxa | ||
Name authority | Mohlenbrock: Brittonia 11: 255, fig. 1. (1959) | Vahl: Enum. Pl. 2: 364. (1805) |
Web links |