Evening Primrose

You have probably heard of evening primrose oil, and all of its wonderful benefits - from aiding skin conditions to lowering blood pressure to helping reduce cramping and breast tenderness in women.  Here's the source of that oil:

Visually, this wildflower really comes into its own in the fall, when its pretty yellow blossoms stand out against the dead and dying grasses around it.

It's a biennial plant, like mullein.  In its first year, it forms leaves close to the ground, in a rosette.  During the second year, the stems grow quite tall ( 6 feet or more) and the blossoms appear, as in this stand that Hyperion is examining, below:

Evening primrose has distinctive, barrel-shaped seed pods, which spiral their way up the stalk like little stair steps.

Another identifying feature is the color of the buds.   They are first green, and then take on a rusty color before blooming.

Parts of the plant are edible, but do your homework first!  Some people are allergic to compounds in the plant.  

The blossoms open in the evening, hence its common name.  The blossoms apparently give off a lemon scent but I did not notice that at the time I took these pictures.  The blossoms open in the evening, hence this plant's common name.

To see very cool videos of blossoms opening in real time, check out this website for Yosemite National Park: 

 http://www.yosemitehikes.com/wildflowers/evening-primrose/evening-primrose.htm

The scientific name Oenothera refers to wine generally.  I read that this name means everything from "wine-scented" to "wine-imbibing".  The jury is also still out on whether this is truly a native species.  Some claim it originated in Europe, but this seems unlikely.