onagra-forms

Updated: May 21, 2025

Following this line backward or downward we reach another apparent mutation-period, which includes the origin of the group called Oenothera, with a large number of species of the same general type as the Onagra-forms, Still farther downward comes the old genus Oenothera itself, with numerous subgenera diverging in sundry characters and directions.

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