This FEIS species review synthesizes information on the relationship of Sonchus arvensis (perennial sowthistle) to fire--how fire affects the species and its habitat, invasiveness of the species, effects of the species on fuels and fire regimes, and fire management considerations. Information is also provided on the species' taxonomy, distribution, basic biology, and general management. This species review can be used for fire management, restoration planning, NEPA documents, and postfire rehabilitation planning. It may also be helpful in wildlife and habitat and invasive species management, and as a source of information on the general ecology of individual species.