Evening Primroses in Early Modern Science

Missouri evening primrose, Oenothera missouriensis

Evening primroses are a group of moderately obscure North America wildflowers (genus Oenothera, evening primrose family, Onagraceae). Unrelated to primroses or roses, evening primroses are pretty and easy to grow, so they have played a solid role in the development of genetics and plant biology.

If you ask, "why do botanists study some plants and not others?" the answers are all very human. Does it grow where they work? Or at a spectacular location where they would like to work? Do they know the plant? That gives showy flowers an edge. Can it be grown easily? Having as many plants as you want allows much better experiments.

Evening primroses do most of those well, so they were noticed by botanists long ago. Which led to publications about their biology, and to more study.

Plant Story--Evening Primroses, Beautiful Whereever You Meet Them

There are 145 species of evening primrose, Oenothera, 80 of them native to the United States.While there are more different species in western North America, the common evening primrose, Oenothera biennis, can be found in all but the Rocky Mountain states.

Evening primroses have big flowers. If you find them open after 7 am or before 7 pm, the flowers are likely yellow. Night-flowering species are often white and close in daylight, so if you are to see them open you need to go out in twilight, wander with a flashlight or get up early. On a cloudy morning they stay open longer, but the white species tend to grow in drier places, where cloudy mornings are less common.

An evening primrose seen in southern Wyoming.

Plant Story--Evening Primroses, Names and Relations

Evening primroses were one of the first midwestern wildflowers I learned. Partly because they are so spectacular

Missouri eveing primrose Oenothera missouriensis in the grassland

I quickly figured out they were not roses or primroses (more on that below). The evening primroses are some 145 species native to the Americas, in the genus Oenothera, in the evening primrose family, Onagraceae. The U.S.D.A. lists 80 species of Oenothera native to North America. With beautiful flowers!

Visiting Northern Colorado--June Flowers at Carter Lake

fringed puccoon, Lithospermum incisum

Check out the flowers at Carter Lake this spring!

This blog post shows flowers from early June 2014--soon to be visible again!

 We drove to the south end of Carter Lake, southern Larimer County, Colorado, and took a casual walk in the campground. It was very quiet on a weekday morning.