Broadleaf Lupine

Lupinus latifolius is a native perennial lupine of western North America, ranging from British Columbia south to Baja California and east to New Mexico. It grows 2–6 feet tall with large palmate leaves and dense spires of pea-like flowers in purple, blue, or white. It supports bumblebees and native solitary bees and serves as a documented larval host plant for several native lycaenid butterflies, including species in the Icaricia complex.

Like all lupines, broadleaf lupine fixes atmospheric nitrogen through root symbiosis with Rhizobium bacteria, making it valuable in habitat restoration and native perennial plantings. It performs best in well-drained, low-fertility soils — fertile amended beds tend to push leafy growth at the expense of flowering. Seeds have a hard coat that benefits from scarification or a 24-hour cold-water soak before sowing. Plants develop a deep taproot and strongly dislike transplanting once established, so site selection before sowing is important. Several subspecies and varieties exist, varying considerably in mature height and flower density.

Indigenous peoples of the Pacific Northwest processed broadleaf lupine seeds as a food source, using repeated water leaching to remove the quinolizidine alkaloids present in raw seeds. These alkaloids make raw seeds and foliage potentially toxic to livestock when consumed in quantity, a relevant consideration in farm-adjacent or grazing contexts.