Oenothera speciosa is a species of evening primrose known by several common names, including pinkladies, pink evening primrose, showy evening primrose, Mexican primrose, amapola, and even "buttercups"
(Wikipedia)
Oenothera rosea, also known as rosy evening-primrose, rose evening primrose, pink evening primrose, or Rose of Mexico, is a plant belonging to the genus Oenothera and native to northern Mexico and Texas.
(Wikipedia)