August Rainlily. This little species Lily, which is native to Argentina, responds to the first good rain in August by putting up white crocus-like flowers on 8" stalks overnight. This is one of the more amazing phenomena in the garden to see how quickly this plant will respond to moisture when it has been deprived for some time. It will continue to flower sporadically into fall. The leaves are a cylindrical dark black-green, which favor wild garlic, except for their color. Few plants are easier to grow in the garden.