Cronartium comandrae (Pucciniomycotina; Pucciniomycetes; Pucciniales; Cronartiaceae) causes Comandra blister rust on pines. This pathogen is native to North America and attacks “hard pines” such as Lodgepole pine (Pinus contorta) and Jack pine (Pinus banksiana). This heteroecious rust fungus requires alternation on two different hosts, the aecial pine host and the telial host, bastard toadflax (Comandra umbellata), a hemiparasitic plant that colonizes more than 200 hosts. The disease has become a problem in areas where pines are planted after logging, insect outbreaks or fire. Tree resistance is being investigated as a way to control this disease. There is a need to further our understanding of how this pathogen can attack and kill pines and to develop tools to monitor the pathogen and prevent the development of new races. The genome sequencing of C. comandrae is part of a larger effort, the "Pathobiome Database For Bioenergy Trees Project" that aims to sequence the genomes of multiple pathogens that share the same host trees in order to identify common and unique genomic signatures. This data will be used to create a database that will help the development of tools for the detection, monitoring and surveillance of pathogens in these economically and ecologically important trees.