Crown of Thorns Plant (Euphorbia milii) 'Care & Types ...The Crown of Thorns (Euphorbia milii) is a resilient, sun-loving succulent shrub featuring thorny stems, green leaves, and colorful bracts (red, pink, yellow, or white) that bloom nearly year-round. Native to Madagascar, it grows 2-6 feet tall, thrives in bright light, requires well-drained soil, and is drought-tolerant, making it a low-maintenance, poisonous, but popular container or landscape plant.