Perennials, 30-80 cm (glabrous or pubescent, mostly on distal peduncles). Stems erect. Leaves sessile; blades linear, 50-100(-130) × 1-4(-15) mm, ± connate, margins entire or spinulose-serrulate. Heads 10-150+, in clusters in corymbiform-paniculiform arrays. Calyculi of 1-3 linear bractlets 1-2.5 mm. Involucres oblong-angular, 3.3-4.5 mm . Phyllaries 5(-6), linear or oblong. Ray florets 0 or 1; laminae yellow, oval to obovate-spatulate, 2-3 mm. Disc florets (2-)5-7(-8); corolla tubes 0.8-1.2 mm, throats basally tubular, becoming funnelform-campanulate apically, 1-1.5 mm. Cypselae linear, 1.2-1.8 mm; pappi 0. 2n = 36.

Flowering year round. Disturbed sites, beaches, hammocks, pinelands; 0-10(-20+) m; Fla.; Mexico (Quintana Roo, Yucatán); West Indies (Bahamas, Cuba).

Flaveria linearis is variable; it typically has linear leaves, calyculi of relatively short, linear bractlets, and oblong-angular involucres. The heads are relatively small with 5-8 florets, and throats of the disc corollas are tubular at the base, abruptly expanding distally to become funnelform-campanulate. Plants of this species, the most common Flaveria in Florida, occur throughout most of the Florida peninsula, often near the coast.