Pipevine Swallowtail caterpillars feed on the leaves of California Pipevine (Aristolochia californica) and absorb chemicals that repel predators. Adult butterflies lay eggs on or near specific plants -- "hosts"-- to provide a food source for the larvae, or caterpillars, when they hatch.

Purple Milkweed (Asclepias cordifolia) with Monarch butterfly caterpillar. The several Milkweed species native to California are host plants for Monarchs. Monarchs migrate from the Sierra to winter on the central California coast.

Kellogg’s Mimulus (Mimulus kelloggii) an annual monkey- flower of the Sierra foothills and a Checkerspot caterpillar. Checkerspots are highly variable in appearance and often use plants of the figwort family (Scrophulariaceae) as hosts.

Yerba Santa (Eriodictyon californicum) with Chalcedon Checkerspot butterflies. The main activities of the adult stage are courtship, mating and egg laying.

Sanborn’s Onion (Allium sanbornii var. sanbornii) visited by a Common Hairstreak. This butterfly uses plants from 20 different families as larval host plants.

Humboldt Lily (Lilium humboldtii ssp humboldtii) flowers attract Pale Swallowtails and other butterflies. Butterflies drink flower nectar (using special mouth parts) and aid pollination of flowers.

Naked Buckwheat (Eriogonum nudum) and Acmon Blue butterfly. The buckwheats one of several larval host plants for Acmon Blues.

Valley Oaks (Quercus lobata) in the Central Valley are host to an undescribed subspecies of California Hairstreak found only in local small communities. Other subspecies of this Hairstreak are common throughout the foothills feeding on other plants. Oak woodlands are important habitats for many butterflies and moths including the California Sister, Golden Hairstreaks, and Dusky-wings. Mistletoe (Phoradendron sp.), a parasitic flowering plant, is host for the Great Purple Hairstreak.

Propertius Dusky-wing warming itself on a rocky hillside. Dusky-wing caterpillars feed on various Oaks (Quercus spp.), found in the Sierra foothills.

Live Forever (Dudleya cymosa) is a succulent plant of rocky outcrops. Dudleya is the host plant for a "local and uncommon" butterfly, the Sonoran Blue, that only lives near the Dudleya and flies in early spring.

Sticky Bush Monkeyflower (Mimulus aurantiacus)

Coyote Mint (Monardella villosa)

Sulfur Flower Buckwheat (Eriogonum umbellatum)

Snowdrop Bush (Styrax officinalis var. redivivus)

Crimson Columbine (Aquilegia formosa)