Elytroderma deformans (Fungi, Ascomycota, Pezizomycotina, Leotiomycetes, Rhytismataceae) causes a needle cast foliar disease on pines. The pathogen infects current year needles in the fall and symptoms appear the following spring when the needles turn bright red, before fading to brown or gray and being cast. Fruiting bodies appear on the upper surface of the needles as longitudinal hysterothecia that eventually split prior to the release of ascospores. The pathogen can become systemic in the shoots and re-infect current year needles. Repeated severe defoliation can result in a “lion’s tail” pattern, causing stunting of the leaders, branches, or needles, that can sometimes appear similar to a candelabra or a broom. The disease can have a severe impact on height growth if it occurs on the upper branches. Attacks by pathogens represent one of the most important threats to the sustainable growth of bioenergy trees in plantations. Outbreak prevention depends largely on a better understanding of how pathogens infect trees so that resistance can be developed and on early detection, monitoring and surveillance to prevent spread. Since pathogens of poplars and pines tend to track their hosts worldwide, we must do a better job at detection and surveillance. This can be challenging since pathogens can remain dormant or have endophytic stages in the host tissues. The genome sequencing of Elytroderma deformans is part of a larger effort, the Pathobiome database for bioenergy trees project, that aims at sequencing the genomes of multiple pathogens that share the same host trees in order to identify common and unique genomic signatures. By sequencing and comparing the genomes of the most important pathogens of poplars and pines, we plan to create a database that will be used to develop tools for the detection, monitoring, surveillance and rapid response of pathogens in these economically and ecologically important trees.