Summary As a species complex, P seudomonas syringae exists in both agriculture and natural aquatic habitats. P . viridiflava , a member of this complex, has been reported to be phenotypically largely homogenous. We characterized strains from different habitats, selected based on their genetic similarity to previously described P . viridiflava strains. We revealed two distinct phylogroups and two different kinds of variability...

Summary The recently discovered ubiquity of the plant pathogen Pseudomonas syringae in headwaters and alpine ecosystems worldwide elicits new questions about the ecology of this bacterium and subsequent consequences for disease epidemiology. Because of the major contribution of snow to river run‐off during crop growth, we evaluated the population dynamics of P. syringae in snowpack and the underlying leaf litter during two yea...