This Costus is often incorrectly identified as Costus sanguineus or a few other names. The name comes from its natural habitat in the seasonally flooded (varzea) forests of the Amazon basin. Costus varzearum is distinctive by its wavy leaves with purple undersides and dark green upper sides. The foliage is very attractive and tropical looking. It grows to about 5 feet tall in light shade to part sun. The flowers appear from early summer to fall on terminal inflorescenses with green bracts. They are a soft creamy yellow with bright red markings on the labellums.
It can be planted in filtered shade to part sun (up to about 2 hours direct sun) in rich, moist, organic soil. It is reported hardy to zone 9 but may be a bit hardier. I have left it outdoors in my Tallahassee zone 8B garden and it has returned just fine in milder winters. It is important not to keep the soil wet during dormancy, or the rhizomes will rot.