What I Identified - Tuft Evening Primrose

Disclaimer: This post is not for identification purposes. Please use wise judgment and use multiple published sources of identification before consuming any wild food.

I live in an area with desert conditions and while going on early spring hikes, the flowy and delicate Tuft Evening Primrose (Oenothera caespitosa) stand out among the cactus and yucca.

I first heard of Evening Primrose when working in a health food store. Commercially the seed oil of another species of Evening Primrose, (Oenothera biennis) is used as a supplement for its source of omega-6 fatty acids, linolenic acid, and gamma-linolenic acid (GLA). As a supplement, it is used for women’s hormonal issues and some skin conditions.

If you look closely, there is a 4 parted sepal.

The way I identify

Currently, my method of identification are my field guides (by picture and region) and Google images, but I am learning a more efficient method in Botany in a Day. After an educated guess I confirmed this belonged to the Evening Primrose (Onagraceae) family and was able to identify the specific species and genera.

“Key Words: Flower parts usually in fours, including a four-lobed stigma.”
Epel, Botany in a Day

Members of the Evening Primrose (Onagraceae) Family have 4 separate petals with 4 separate sepals. “There are an equal number or twice as many stamens as petals. It has a compound pistil with styles fused together, but not the stigma lobes.”, Epel.

The stigmas make an X shape. Tuft Evening Primrose has these characteristics plus a basal rosette of long, thin, and lobed leaves.

8 stamens and 4 parted pistil forming an X.

An evening bloomer

Some members of this genus (including this one) open in the late afternoon to evening and are pollinated by hawkmoths at night (hence ‘evening’ primrose). The white flowers of Tuft Evening Primrose wilt to a pink color the following day.