4a. Symphyotrichum subulatum (Michaux) G. L. Nesom var. ligulatum S. D. Sundberg, Sida. 21: 907. 2004.
Saltmarsh or southern annual saltmarsh aster
Aster subulatus Michaux var. ligulatus Shinners, Field & Lab. 21: 159. 1953; Symphyotrichum divaricatum (Nuttall) G. L. Nesom
Plants (10–)60–200 cm. Stems usually simple, sometimes branched proximally. Heads 15–120, in open, diffuse arrays, secund on primary branches longer than peduncles. Involucres (5.2–)6–6.9 mm. Phyllaries 25–45(–62), subulate to lanceolate, narrow, green zones narrowly lanceolate. Ray florets 17–30(–45) in 1 series; laminae lavender to blue, (3.5–)4.5–7 × 0.9–1.3 mm, longer than pappi, drying in 3–5 coils (apices shallowly lobed). Disc florets (20–)33–50; corollas 3.7–4.5(–5) mm. Cypselae (1.3–)1.7–2.5(–2.9) mm; pappi (3–)3.5–4.6 mm. 2n = 10.
Flowering Jul–Nov(–Feb). Marshy habitats, often weedy, roadsides, lawns, waste places; 0–1500 m; Ala., Ark., Kans., La., Miss., Nebr., N.Mex., Okla., Tenn., Tex.; Mexico (Chihuahua, Coahuila, Tamaulipas).