a similar and related North American plant, Malcolmia maritima
See full dictionary entry for stock
Virginian stock in British English
(vəˈdʒɪnɪən stɒk)
noun
a North American plant, Malcolmia maritime, related to stocks of the genus Matthiola, such as M. incana and M. bicornis (evening or night-scented stock), of the Mediterranean region, cultivated for their brightly coloured flowers: Brassicaceae (crucifers)