Epilobium septentrionale, commonly known as Northern Willowherb, is a deciduous perennial herb native to chaparral, coastal sage scrub, and open woodlands in California. It thrives in dry, rocky areas, including riverbanks, cliffs, and slopes. This plant typically forms clumps and grows in thin patches of soil between rocks, reaching a modest height. The leaves are oval, pointed, glandular, and covered in a coat of white fuzz, which helps in reducing water loss. The bright red-orange tubular flowers, measuring 2 to 3 centimeters long, are borne on glandular inflorescences at the end of erect branches. The flowers, which are pollinated by nectar-feeding birds, are quite showy with a bunch of stamens and a long pistil protruding from the bloom. The fruit is a hairy capsule about two centimeters long, which aids in seed dispersal.

Northern Willowherb is appreciated for its bright, attractive flowers and its ability to thrive in challenging, dry conditions, making it suitable for rock gardens, xeriscaping, and restoration projects. It is often used to stabilize slopes and prevent erosion. In cultivation, it requires full sun exposure and can tolerate low to medium water conditions, adapting to various soil types with different drainage rates. While it is not commonly affected by diseases, it can be susceptible to root rot in overly wet conditions. Gardeners should be aware of its potential to spread in favorable conditions, which can be managed by deadheading spent flowers to prevent excessive self-seeding.CC BY-SA 4.0