Amer. J. Bot. 83: 369. 1996
Annuals or perennials, 10–70(–100) cm, herbaceous to suffrutescent. Leaf blades oblong to oblanceolate, mid-cauline (2.5–)4–13 mm wide. Heads essentially sessile, often surpassed by distal leaves that continue to very base of heads. Involucres (6–)10–15 × 12–30 mm. Phyllaries in 3–4 series, loose, subequal, apices erect to spreading, 1.3–1.7 mm wide, herbaceous. Ray florets 17–38; corollas 8.5–19 mm. Disc florets: corolla tubes longer than limbs. 2n = 12.
Phenology: Flowering (Jul–)Sep–Dec (sporadically Feb–Jun).
Habitat: Sandy sites, along waterways, canal banks, dunes, beaches, salt flats
Elevation: 0–10 m
Colo., Fla., La., Tex., Mexico (Tamaulipas).