Monocostus is a genus in the plant family Costaceae with only one species - Monocostus uniflorus. This species is only known from a small area in northern Peru near the city of Tarapoto. I tried in vain to find it in 2008 and I fear it may now be extinct in the wild. Fortunately someone collected it years ago and placed it in cultivation for all to see.
It is a gorgeous little plant! The bright yellow flowers arise from the leaf axils amid a sea of small green rounded leaves that have a bit of a waxy feel. The plant grows to no more than 18 inches tall and is very easy to grow in pots if you are in an area too cold for outdoors growing in the winter. It flowers easily and is very showy in the pot or garden.
It is reported to have grown in steep rocky areas in nature and does seem to prefer very good drainage, but regular moisture. I doubt it is hardy outdoors in colder areas than USDA zone 10 or 9B at best.