Cyperus hermaphroditus |
Cyperus giganteus |
|
---|---|---|
hermaphrodite flatsedge |
giant flatsedge, Mexican papyrus |
|
Habit | Herbs, perennial, rhizomatous. | Herbs, perennial, rhizomatous, stout. |
Culms | trigonous, (10–)30–80(–140) cm × (0.4–)1–3(–5) mm, glabrous. |
roundly trigonous, 200–350 cm × 15–50 mm, glabrous. |
Leaves | V-shaped or flanged V-shaped, (5–)15–70(–90) cm × (2–)4–10(–13) mm, glabrous. |
bladeless. |
Inflorescences | spikes 1(–5), rather densely ovoid or oblong-cylindric, (10–)25–45(–62) × 7–22 mm, 11–21 spikelets per 5 mm of rachis; rays (3–)5–10(–17), (1–)5–12(–24) cm; bracts (2–)4–8, ascending at 30–45°, V- or inversely W-shaped, (2–)8–40(–65) cm × (1–)2–8 mm; rachilla deciduous, wings 0.4–0.5 mm wide. |
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 | (10–)50–150, oblong to linear, quadrangular, (3–)4–8(–18) × (0.8–)1–1.2(–1.6) mm; distal spikelet spreading or ascending; floral scales (1–) 3–8, pale greenish white to golden brown, deep brown, or reddish brown, medially usually green, weakly to strongly 3(–4)-ribbed laterally, 1–3-ribbed medially, ovate to elliptic, (2–)2.6–3.2(–4) × 1.2–2 mm, apex 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 (0.4–)0.6–1 mm; styles 0.4–1.6 mm; stigmas 1–1.5 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 | brown or reddish brown, sessile or nearly so, ellipsoid, 1.4–1.8(–2) × 0.6–0.8(–1) mm, apex acute to obtuse, slightly apiculate, surfaces puncticulate. |
pale brown, sessile, oblong, 0.9–1 × 0.4–0.5 mm, apex scarcely apiculate, surfaces puncticulate. |
Cyperus hermaphroditus |
Cyperus giganteus |
|
Phenology | Fruiting summer–fall. | Fruiting summer. |
Habitat | Arroyos | Stream banks, marshes |
Elevation | 500–1200 m (1600–3900 ft) | 0–10 m (0–0 ft) |
Distribution |
AZ; TX; Mexico; South America; West Indies |
LA; TX; Mexico; Central America; South America; West Indies [Introduced in North America] |
Discussion | An erroneous report of Cyperus hermaphroditus from Alabama was based on misidentification of C. thyrsiflorus. (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, p. 186. | FNA vol. 23, p. 173. |
Parent taxa | Cyperaceae > Cyperus > subg. Cyperus | Cyperaceae > Cyperus > subg. Cyperus |
Sibling taxa | ||
Synonyms | Carex hermaphrodita, Mariscus hermaphroditus, Mariscus jacquinii | |
Name authority | (Jacquin) Standley: Contr. U.S. Natl. Herb. 18: 88. (1916) | Vahl: Enum. Pl. 2: 364. (1805) |
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