The Madagascar native crown of thorns (Euphorbia milii var. sonorae) blooms in masses of bright pink flowers throughout the winter. Its succulent stems are armed with thorns and its sap with distasteful chemicals, both of which discourage herbivores from feeding on the tissues. Grown indoors on bright windowsills with almost no water during the summer, this long-lived plant continues to reward such inattention with masses of blooms. The variety name is of dubious validity, but it differs from the species with larger leaves and more flowers.