This weedy biennial is thinly scattered across northeastern and northwestern regions (especially Wash.), but it is not much established in North America. The only record from Ky. is the obscure report by McMurtrie (1819). A. caucalis M. Bieb. is a European annual that may be expected (Ch, J, Y); it has more hispidulous leaves and prickly fruits (2n = 14 versus 16). Also, the cultivated "garden chervil" is A. cerefolium (L.) Hoffm., an ancient culinary herb from Europe; it reportedly escaped at scattered sites across northern states and adjacent Canada, but not Ky. (K).