Mini crown-of-thorns (Euphorbia milii var. splendens) is a slow-growing tropical shrub with a rambling growth habit. Plants can grow to 1 foot by 2 feet on this Madagascar native that may be extinct in the wild. Its 5- to 6-sided fleshy, thorny stems are adorned with short, oblong leaves. The inconspicuous flowers, called “cyathia” are surrounded by colorful red bracts. At the Chicago Botanic Garden, crown-of-thorns bloom all 12 months of the year in the greenhouses. Plants require full sun, moderate temperatures, and low humidity. It's a perfect addition to the desert garden.

The milky latex sap of this Madagascar native "bleeds" when stems are cut; the bleeding can be stopped by immersing the stems in warm water. The Euphorbiaceae is a very large family, containing more than 2,000 species, including the popular poinsettia.