Fusarium circinatum is a fungal plant pathogen that causes the serious disease pitch canker on pine trees and Douglas firs (Pseudotsuga menziesii). The most common hosts of the pathogen include slash pine (Pinus elliottii), loblolly pine (Pinus taeda), Monterey pine (Pinus radiata), Mexican weeping pine (Pinus patula), and Douglas fir. Like other Fusarium species in the phylum Ascomycota, it is the asexual reproductive state of the fungus and has a teleomorph, Gibberella circinata.