The taxonomy of the genus Draba is extraordinarily complex, particularly for Draba verna, which is sometimes treated as a whole genus (Erophila DC.) in its own right, with a number of different species and varieties listed under various treatments. The reason for this is that D. verna reproduces almost entirely by inbreeding (the flowers pollinating themselves immediately on opening), so a large number of genetically similar lines can be recognised. These lines can even have different chromosome numbers (or ploidy levels), making them less compatible with other plants even when cross-pollination does occur. A full list of synonyms, subspecies and varieties is given in the Brassicaceae Species Checklist. The account here is for Draba verna L. in its original, aggregate, sense, although D. praecox and D. majuscula can be viewed as separate species.
