Under various synonyms, this tetraploid (2n = 28) winter annual, flowering mostly during Mar-May in Ky. but occasionally (in 2024) as early as Jan. It was first reported in North America by Rafinesque in 1832 (Pennell 1935), then by Gray (1889) as "rare in Atlantic states". V. persica is now widely scattered across temperate regions. The earliest Ky. record was provided by McFarland (1942); B did not include it. Distinction of persica from agrestis and polita is often difficult. It tends to have larger flowers, with deeper blue corollas 8-12 mm wide (versus 4-8 mm), longer pedicels (up to 15-40 mm versus 6-15 mm), and fruits with more divergent lobes (at ca. 90 degrees versus less). V. persica appears to have originated from polita and another diploid parent in the Caucasus region. It started to spread across Europe during the Neolithic era but did not reach Britain and North America until after 1800 (Fischer 1987). In Britain, Boutin & Harper (1991) found that germination occurs in fall, spring and summer; but colls.from Ky. (flowering or fruiting) date only from Mar to May.