This cultivated alien rarely persists or spreads; there are scattered records from the Bluegrass region (BOON, FAYE, SCOT). This species is easily confused with Stylophorum diphyllum (FNA 3, W). Stigmas are 2-lobed (versus 3-5); styles are 1-5 mm long (versus 3-6 mm); capsules are 2-valved (versus 3-4), dehiscent from base (versus apex), linear (versus ellipsoid) and smooth (versus pubescent). Cauline leaves are alternate, versus subopposite in Stylophorum; less pale below, and they tend to be smaller (up to 35 cm long versus 50 cm) with petioles 2-10 cm long (versus up to 20 cm). The word "celandine" has been used in the common names for both species, which is unwise; it should be restricted to Chelidonium; see also Ficaria verna.