Crown of Thorns Cheetah has large, 1 yellow blossoms with a splattering of red throughout the petals. It puts on an amazing floral show during the spring and summer blooming season. Euphorbias are indestructible houseplants that thrive on neglect. Be sure to let the soil dry out between waterings. This easy-care plant will thrive on a sunny windowsill or grow it outside during the warm summer months.