Aster L.
Involucre 2–4 mm diam. Leaves 10 mm wide, linear-lanceolate, up to 12 cm long, sessile. Heads in a large loose leafy panicle. Ray florets female; rays white pink or blue. Cypselas 2 mm long. Pappus bristles 5–7 mm long. Erect, almost glabrous herb up to 2 m high. Widespread. Weed of cultivation and waste places, often in wet ground; margins of saltmarshes. Introd. from America. Fl. chiefly winter. Bushy Starwort Aster subulatus
Involucre 5–7 mm diam. Leaves 12–20 mm wide, 6–8 cm long, sessile, stem-clasping, lanceolate, usually with a few small teeth. Rays blue-purple. Rhizomatous perennial up to 30 cm high. Widespread. Weed near habitation. Introd. from Europe. Michaelmas Daisy or Easter Daisy Aster novi-belgii