Costus letestui is a very different kind of Costus with large waxy leaves and large white flowers that can appear any time of year. This Costus is a lateral bloomer, meaning that the inflorescences form at the leaf axils - and also sometimes at the base. The form of this African species is somewhat like the yellow flowering Costus lateriflorus or the pink flowering Costus talbottii, but the white flowers are larger and showier.
The plant is easilly grown and will flower in a 6-8 inch pot, maturing at about 2 feet in height and width. The size makes this an ideal houseplant that can be grown outdoors in summer and indoors (or in a greenhouse) in winter. It seems to prefer medium shade. Hardiness has not been tested, but I doubt it would be winter hardy except in frost-free locations. I grow it in a loose, free draining peat and perlite mix with light applications of slow release fertilizer.