Dwarf Evening Primrose Oenothera caespitosa
There are a few types of primrose that we commonly see around the Moab. This one has many common names: Tufted, Dwarf Evening, or Fragrant Evening to name a few. It has a rather showy flower that blooms in the evening, stays open all night, and then wilts in the morning. The other common types of Primrose we see around here are the Pale Evening Primrose (Oenothera pallida) and the Bridges Primrose (Oenothera longissimi). These are all part of the Onagraceae or Evening-primrose Family. They all bloom in the evening and will wilt with the sun’s rays in the morning.
The Primrose, and some other evening bloomers, is dependent on Hawk Moths, or Sphinx Moths for pollination. Sphinx Moths are a large type of moth that usually has a long “nose” or proboscis designed for feeding on nectar. Some have the ability to hover while feeding and therefore are commonly mistaken for hummingbirds. In the larvae stage Sphinx Moths are a medium to large caterpillar and most have a horn on their tail, earning them the name hornworms. When at rest these caterpillars raise up their heads and their front feet in a praying pose which is how the Sphinx Moth got its name.
I found this primrose out at the Bar M biking area on an evening ride. After the flower wilts it turns pinkish to purple. You can find these guys blooming from spring all the way into late summer.