draba

Updated: May 17, 2025

In such groups of nearly allied forms the single members must evidently be of common origin. It is not necessary for them to have originated all in the same place or at the same time. In some cases, as with Draba verna, the present geographic distribution points to a common birthplace, from whence the various forms may about the same period have radiated in all directions.

Hugo de Vries - Species and Varieties, Their Origin by Mutation