Wolf’s evening primrose (Oenothera wolfii) is a rare, native, short-lived perennial restricted to a small area on the coasts of Northern California and Curry County Oregon. Its habitat is moist and/or sandy places close to the ocean at less than 300 feet. These Wolf’s evening primrose specimens were growing on Preston Island immediately west of Crescent City CA (Del Norte County). I do not know why this location is called an “island” as it is more of a very small rocky peninsula jutting out into the Pacific.
In the first year the plant puts out a basal rosette of narrow lanceolate to elliptical leaves. The following year the plant bolts and flowers. The thick, reddish Wolf’s evening primrose stems have some stringose (stiff, closely appressed) hairs. The cauline leaves are alternate and closely spaced. Green, withering to red, the leaves have wavy and/or shallowly toothed margins.
At the top of the stem are the bright yellow flowers. Each flower has four hairy, reddish-green sepals and four large petals which become orange then red as they wither. The Wolf’s evening primrose ovary is inferior, long and slender with one style and a four-lobed stigma.
The fruit is an elongated reddish, soft-hairy capsule which splits at maturity to release many seeds.
O wolfii readily hybridizes with large-flowered evening primrose (O glazioviana), an introduced ornamental species. The hybrids can be difficult to distinguish. However, the petals of “pure” Wolf’s evening primrose do not overlap while those of large-flowered evening primrose do overlap. A synonym for Wolf’s evening primrose is Oenothera hookeri ssp wolfii.
The leaves and stems of Wolf’s evening primrose are mucilaginous. A tea made from this plant can be used to treat sore throat and coughs. Evening primrose salves reduce swelling.
The species designation honors Dr. Carl Brandt Wolf (1905 – 1974), a botanist at Rancho Santa Ana Botanic Gardens (California).