Genus of about 90 species of mostly clump-forming, rhizomatous perennials with an open, lax habit, found on forest floors in tropical Africa, Asia, Australia, and North, Central and South America. Costus is a plant for a greenhouse or conservatory. The leaves are large and they spiral around the stem. The flowers appears in late spring - they are colourful but short-lived. Costus has a resting period in winter.