Southeastern annual saltmarsh aster

Conyza squamata Sprengel, Syst. Veg. 3: 515. 1826; Symphyotrichum squamatum (Sprengel) G. L. Nesom

Plants 30–150 cm. Stems simple or branched basally. Heads 30–100 in open, diffuse arrays, secund on primary branches longer than peduncles. Involucres 5–7(–8) mm. Phyllaries 18–24(–30), subulate to lanceolate (often broadly so), green zones broadly lanceolate, absent from proximal portion. Ray florets 21–28(–38) in (2–)3 series; laminae white (drying white or lavender), 1.3–1.7(–2) × 0.2–0.3 mm, shorter than pappi, drying in inward curls, rarely coiling. Disc florets (3–)7–14, 4–4.9 mm. Cypselae 1.5–2.6(–3) mm; pappi 4–5.1(–5.3) mm. 2n = 20.

Flowering Jul–Nov. Salt marshes, brackish marshes; 0–10 m; introduced; Ala., Fla., La., N.C., Tex.; Bermuda; South America; introduced in Europe (France), Asia (Iraq, Japan), Australia, and elsewhere.

The name Aster subulatus Michaux var. sandwicensis (A. Gray ex H. Mann) A. G. Jones (Brinttonia 36: 465. 1984) has priority at the varietal level; the combination in Symphyotrichum has yet to be made.