Crossandra, otherwise known as the "firecracker flower," is a tropical plant known for its brilliant clusters of brightly colored blooms and waxy green leaves. Crossandra can be grown outdoors as an annual or a perennial depending on how warm it is where you live, and it does well indoors as a houseplant. Crossandra is native to Sri Lanka and southern India, favoring tropical and humid conditions. Crossandra grows best when placed in bright, indirect sunlight and planted in soil on the acidic side.