Although the costus has been propagated for the commercial nursery trade for quite some time, there is so little that we know about this incredibly diverse group of plants. Those that we come across in the nursery trade probably constitutes less than 20% of the species that has been discovered. This explains why there is a dearth of literature about the costus, either in books or on the web. If not for Dave's website, we wouldn't know that there are more than a hundred over different species of costus spread over several continents.
Unlike most other gingers, the costus is probably the most underrated plant in the zingiberaceae family. Only a couple of handful of species and hybrids ever make it as landscape plants, probably due to the fact that it is not as free-flowering as its cousins, the heliconias or the curcumas. Still, I find that the foliage and its spiraling effect lends texture to a heavily-planted tropical garden.
I found these growing in Ryan's garden. At the time, he didn't know what this was. Well, Dave didn't know either. Several months later, Ryan asserted that this was a natural hybrid consisting of the Costus peruvulentus x barbatus. Well, he can call it whatever he wants because no one out there would have a clue.