This lupine, along with five others, is poisonous from the time it starts growth in the spring until the seed pods shatter in late summer or early fall.

It, along with poison hemlock (Conium maculatum) and tree tobacco (Nicotiana glauca), induced "multiple congenital contractures (MCC) and palatoschisis in goat kids when their dams were gavaged with the plant during gestation."

The skeletal abnormalities included fixed extension of the carpal, tarsal and fetlock joints, scoliosis, lordosis, torticollis and rib cage problems.

The clinical signs of toxicity in sheep, cattle and pigs included, ataxia, incoordination, muscular weakness, prostration and death.

robustus is confined to the Sierra Nevada and the Southern Coast Ranges of California, while var formosus is more widespread.