Photo Credit: Flickr Commons

Every second Saturday of the month, CWC (Coastal Watershed Council) leads River Health Days where volunteers help plant and care for a variety of native plant species to increase biodiversity and habitat complexity and support a healthy river ecosystem. Hooker’s Evening Primrose (Oenothera elata) is one beneficial plant you may spot growing along the river.  


Primrose is a perennial or biennial herb found in a variety of habitats including wetlands, seasonally wet areas, and disturbed areas. They are native to California, but their range extends throughout North America. Although they have a short lifespan, they are prolific seed producers allowing them to continue benefiting habitat by creating offspring. They can grow up to five feet tall and can extend to three feet wide. They have beautiful large yellow to orange blooms coming from a basal rosette. They have a deep taproot that makes them drought tolerant. 

Ecological Significance 

The name evening primrose comes from the fact that it closes it bloom midday and opens it in the evening. This allows them to be pollinated in the evening by sphinx moths. They are also pollinated by other evening pollinators including the twilight-foraging carpenter bee.  

Evening primrose is an important food source. It provides nectar not just for insects, but also for hummingbirds. It also provides seed for birds including the Lesser goldfinch. Lastly the ground squirrels on the San Lorenzo River love to climb up it to grab a little seed or flower snack. 

Traditional Uses 

The Zuni people created a powder using evening primrose along with salvia to create a poultice to decrease swelling. A sister of Hooker’s Evening Primrose named Common Evening Primrose was used by the Cherokee, Iroquois, Ojibwas, and Potawatomi. It was used medicinally and as a food source. The roots were boiled and eaten like potatoes, the leaves were eaten as greens after being cooked, and the shoots were eaten raw. Like the Zuni people these tribes also used common evening primrose in a poultice. This poultice was used to treat bruises, piles, and boils. Along with all these uses Common Evening Primrose was also used in various forms to treat laziness, menstrual pain, bowel pain, and increase strength.  

Modern Medicine Uses 

The sister of Hooker’s evening primrose, Common Primrose, is used throughout the United States for its confirmed herbal properties, and its assumed herbal properties. It is often used in the form of an oil derived from its seeds. It is used to treat eczema, arthritis, PMS, breast pain, diabetes, menopause symptoms, ADHD, asthma, high cholesterol, obesity, hepatitis B, liver cancer, breast cancer, and other ailments. It is also widely used in skin care products to clear up acne and improve overall skin health. 

CWC & Hookers’ Evening Primrose 

Coastal Watershed Council has previously planted Hooker’s Evening Primrose at our habitat enhancement site. Many of our original plants are no longer there because of their short-lived nature, but luckily the seeds have travelled down to the river’s edge where they have created large stands of brilliant yellow flowers. 

Love Primrose? Join CWC for a River Health Day! 

You can make a difference in the San Lorenzo ecosystem by caring for Evening Primrose and other native plants that enhance the ecological value of San Lorenzo River habitat. Join other volunteers at monthly River Health Days to plant more native species. Sign up below!  


Facebook Comments