Thamnosma montana (Rutaceae)
Thamnosma montana (Turpentine broom - sometimes run together as Turpentinebroom), a native desert plant in the Citrus family, is a larval host of the Desert Black Swallowtail. Seeds are dispersed after being eaten by animals. The plant only has leaves after heavy rains.
Flowering Thamnosma montana. This plant is found in our deserts up to 5500', and is present all along Cactus Spring Trail, which is typified by Pinyon Pines and California Juniper.
A Desert Black Swallowtail larva on host Thamnosma montana. It was eating the green stem.
Flowers (left) are purple; seed capsules (right) are yellow and have 1 to 3 seeds each.