Florida Amaranth

Stems erect, branched, slender, usually (0.5-)1-1.5 m. Leaves: petiole ¹/4 length of blade; blade linear to narrowly oblong, usually 10(-20) × 1 cm, base narrowly cuneate, margins entire, plane, apex obtuse to rounded. Inflorescences terminal, linear spikes to panicles. Bracts: of pistillate flowers 1-1.5 mm; of staminate flowers with moderately heavy midrib, 1-1.5 mm. Pistillate flowers: tepals 1-2(-3), unequal, inner tepals lanceolate to narrowly lanceolate, 1-1.5 mm, apex acute to acuminate; style branches spreading; stigmas 3. Staminate flowers: tepals 5, with excurrent midrib, equal to subequal, 2(-2.5) mm, apex acute to indistinctly mucronulate in outer tepals; stamens 5. Utricles reddish to reddish brown, occasionally with indistinct longitudinal ridges, subglobose to broadly obovoid, 1.5-2.5 mm, wall thin or slightly fleshy, irregularly rugose. Seeds dark reddish brown to dark brown, 0.7-1 mm diam., shiny.

Fla.

Flowering late spring-fall.

Coastal dunes, beaches, swamps, marshes, disturbed habitats, such as gardens and fields near coast; 0-10m.

Acnida floridana S. Watson, Proc. Amer. Acad. Arts 17: 376. 1882

Acnida floridana S. Wats. Proc. Am. Acad. 17: 376. 1882
Plants glabrous throughout, or sparsely villous on the younger parts; stems slender, erect or ascending, 4-15 dm. long, simple, or branched at the base, palegreen, smooth or striate; leaves few and remote, the petioles 4-30 mm. long, slender, the blades linear, oblong-linear, or narrowly oblong, 0.8-10 cm. long, 2-10 mm. wide, rounded at the apex, attenuate at the base, paleor yellowish-green; spikes 1-5 dm. long, very slender, 3-10 mm. thick, composed of numerous, usually remote, sometimes approximate, sessile, few-flowered clusters, flexuous, often recurved; sepals oval or ovate, 2 mm. long, obtuse to acute, mucronate, thin, longer than the triangular-lanceolate bracts; bracts of the pistillate flowers lanceolate or ovate, rigid, equaling or shorter than the utricle, green, often tinged with red, pungent; utricle 1.2 mm. long or less, 3-angled, thin but somewhat fleshy, more or less rugulose, often tinged with red; seed rotund, 0.8 mm. in diameter, smooth, black and shining.
Type locality: Key West, Florida. Distribution: Florida.

Amaranthus floridanus, the Florida amaranth, is a flowering plant endemic to Florida.

Amaranthus floridanus flowers from late spring to fall and can grow up to 1.5 m in height. It usually grows in moist places, near dunes, swamps, marshes, or in disturbed habitats.