Six species of Melampsora: M. salicis-albae, M. larici-pentandrae, M.
amygdalinae, M. capraearum, M. ribesii-viminalis and M. epitea, were i
dentified among 26 willow leaf samples collected mainly in SW England.
Identification of species was based on the morphology of the uredinia
l and telial stages as well as on the results of inoculations of the a
ecial hosts. M. epitea occurred alone in 18 leaf samples, and together
with M. ribesii-viminalis in one further sample. Basidiospores produc
ed from teliospores of the autoecious M amygdalinae infected Salix tri
andra (a species of tree willows). All other species were heteroecious
, with M. laricipentandrae, M capraearum and M epitea producing spermo
gonia and aecia on Larix decidua (European larch), and less readily on
L. kaempferi (Japanese larch). M. ribesii-viminalis and a form of M.
epitea from S. purpurea, occasionally formed spermogonia but not aecia
on Ribes spp. M. epitea, M. capraearum, and M. ribesii-viminalis occu
rred on cultivars of shrub willows which are favoured for short-rotati
on, coppiced energy cropping in the U.K.