Butterfly and Pollinator Friendly Plants
Includes two kinds, those that are host plants for specific butterfly species and those that are attractive to a wide range of butterflies.
In the first case, species that are required, or obligate, host plants, or nurseries, for certain species of butterflies are part of an ancient relationship between butterflies and plants. It goes like this: the adult butterfly lays eggs on the host plant. When the eggs hatch into caterpillars, they find that this plant can supply just the right nutrients or other chemical substances that they need to go through their different larval stages, finally turning into a chrysalis. The chrysalis eventually becomes the adult butterfly that we all enjoy in our gardens and in the wild.
This plant may provide them with certain toxins that help protect them from predators, as is the case with the monarch and the milkweed. It may protect them or shade the caterpillars in just the right way. Without these host plants, that particular butterfly cannot reproduce and survive. This is a very specific kind of co-evolution. Buckwheats (Eriogonum species) for example, often are host plants for certain butterflies. In LA, the El Segundo Dunes contain coast buckwheat (Eriogonum parvifolium) which is the host plant for the El Segundo Blue Butterfly. When Eriogonum fasciculatum was mistakenly planted, it fostered other species that outcompeted or parasitized the El Segundo Blue. The details matter.
Many LA beaches were home to a specific butterfly/host plant relationship that disappeared when invasive species, development, or other factors eliminated the host plant. Host plants are part of this particular insect/plant relationship enabling reproduction. Many of them also provide nutritious nectar or places to lay eggs for a number of species as well.
Those species that are particularly hospitable to providing a wide range of California insects with what they need. Some "super-pollinator plants" are particularly conducive to a wide range of insect life, species that will give you a good start if you want to support pollinators in your garden.
Most plants that are not wind-pollinated are pollinated by insects. Grasses and conifers are wind-pollinated, and most of the rest, the annual and perennial wildflowers and trees and shrubs, are insect-pollinated. The shared co-evolutionary history of our flora with our insects is one of the most compelling reasons for growing California native plants in your garden and supporting their continued presence in our wildlands. Though many commonly used garden plants can supply nectar to generalist bees, butterflies, and other insects, native plants do it just right - the right timing, the right nutritional content, and the right floral structure.