Lupinus truncatus, commonly known as Collared Annual Lupine, is an annual herb native to the chaparral and coastal sage scrub of southern California and Baja California. It typically grows up to 1.6 feet tall and features palmate leaves composed of 5 to 8 narrow leaflets. The plant is known for its striking magenta or reddish-purple flowers with distinctive yellowish patches, which bloom in dense racemes during the spring season. The flowers are followed by hairy legume pods that are about 1 inch long. Collared Annual Lupine is particularly adapted to the Mediterranean climate of its native range, with mild, wet winters and hot, dry summers.

Collared Annual Lupine is valued for its vibrant flowers that add a splash of color to wildflower gardens, meadows, and restoration projects. It is also used in native plant gardens to support local pollinators. This species prefers full sun to light shade and requires well-drained soils. While it is drought-tolerant once established, it benefits from occasional watering during prolonged dry periods. It is generally easy to maintain, but it can be susceptible to fungal diseases if conditions are too moist. Collared Annual Lupine is not known for aggressive roots or significant pest problems. However, it can self-seed prolifically under favorable conditions, which should be considered in garden planning.CC BY-SA 4.0