The Upper Klamath River Canyon is very diverse both botanically and ethnobotanically. This situation might sound good except for the fact, noted most often in tropical regions, that high diversity generally equals low productivity. One plant within the study area which does not fall into this trap is the genus Perideridia. This plant, called Ipos by the Shasta, has maintained this situation due to its unique interactions with various aspects of its environment, including people. This paper will examine these interactions as well as the place which this plant might thus have occupied within the subsistence economy of the people who inhabited the canyon.