This showy blue flower from southern Europe is widely grown for ornamental use and sometimes culinary use (in its aromatic seeds). Although escapes have been reported in North America, especially northeastern states, no reports have come from Ky. (K, W). Nigella is somewhat similar to Delphinium but differs as follows (FNA 3; W): flowers solitary, subtended by a finely divided involucre (versus in a raceme, not subtended by involucres); fruit a spherical capsule-like structure composed of 5 or 10 partially connate follicles, each follicle terminated by a linear beak 13-20 mm long (versus fruit follicular, each with a 1-2 mm long beak).