What is "playas"

Usage examples of "playas".

On these great playas and on the frost-caked walls of channels, cliffs, and calderas, transplanted lichen had clung and leapt into devouring life.

What you do must match the others, so I encourage you to talk to each other about this--and, most of all, to listen to me because I have no instrument to handle and I alone can see the playas a whole.