The long, four-parted woody fruit capsules of common evening primrose (Oenothera biennis) are readily recognizable even in winter. These capsules are arranged in spikes at the tip of the stem. Common evening primrose often grows as a single tall stem, 3 to 6 feet tall, but can develop multiple branches. In the case of a plant having more than one branch, each stem tip will produce a spike of flowers, and ultimately a spike of these woody capsules. The seeds within these capsules provide food for many bird species during the winter months, and are a favorite of goldfinches.

As the species name “biennis” suggests, common evening primrose is a biennial plant (i.e., each individual lives for two years). If you look carefully on the ground around this year’s dead stalks, you can find the rosette of basal leaves that will send up next year’s flowering shoot. If you’d like to try to find common evening primrose search in dry open fields, along roadsides, railroad embankments, and disturbed areas where this plant is often found.