A. autumnalis: annual, erect, one foot high, glabrous or slightly downy; leaves triply pinnatifid, with narrow linear segments; flowers bright scarlet, with a dark spot at the base of the petals; carpels numerous, collected in ovate or oblong heads. - Cornfields. Fl. July or October.
A variety with larger flowers is cultivated in flower-gardens, under the name of Flos Adonis.