Milkweed

A short-lived perennial herb with clusters of orange and yellow flowers, best known as the primary host plant for Monarch and Plain Tiger butterfly caterpillars. Contains a latex sap that is mildly toxic if ingested. Without milkweed, these butterflies cannot complete their lifecycle in a garden at all, since caterpillars feed exclusively on its leaves; the flowers also draw bees and other nectar feeders, making it one of the highest-impact single plants for butterfly conservation.