1. Cladium jamaicense Crantz, Inst. Rei Herb. 1: 362. 1766.
Cladium mariscus (Linnaeus) Pohl subsp. jamaicense (Crantz) Kükenthal; Schoenus cladium Swartz
Rhizomes to 20 cm × 10 mm. Culms 1–3 m × 5–10 mm. Leaves: blades flat to broadly V-shaped, 5–11 mm wide, margins and midvein abaxially harshly scabrous with teeth visible to unaided eye. Inflorescences terminal (or lateral and terminal), 30–50 cm; 1st, 2d, 3d, and some 4th order branches, branches slightly flexuous. Spikelets in groups of 2–3(–6), narrowly ellipsoid to lanceolate; floral scales 5–6, the proximal chestnut brown, ovate to oblong-lanceolate, 2.5–3 × 2 mm, midvein conspicuous, lateral veins weak; stamens 2; anthers 2 mm, connective apices 0.1–0.2 mm; styles 2–2.5 mm; stigmas 1–1.5 mm. Achenes light greenish brown, ovoid, 2 × 1 mm, glossy, base vaguely 3-lobed, truncate, not flared or discoid, apex acute, irregularly rugulose longitudinally.
Fruiting spring–summer. Coastal brackish and fresh marshes; 0–100 m; Ala., Ark., Fla., Ga., La., Miss., N.C., S.C., Tex., Va.; Mexico; West Indies; Central America; n South America.
Cladium jamaicense is important as the dominant species in much of the Florida Everglades (K. K. Steward and W. H. Ornes 1975).
Steward, K. K. and W. H. Ornes. 1975. The autecology of sawgrass in the Florida Everglades. Ecology 56: 162–171.