The Oenothera genus consists of more than 80 species of annuals, biennials, and perennials, many of which spread freely in the meadows, roadsides, and prairies of North America. Individual flowers last only one day or one night. 'Siskiyou' is a cultivated version growing 15 inches tall, covered all summer with a mass of 2-inch, cup-shaped, fragrant pink flowers with white centers. The veining on each petal resembles the wing of a butterfly and glows when backlit by the sun. Well suited to hot dry sites, it is ideal as a ground cover, in rock garden, or in containers.