Comparative studies of Drepanopeziza species
pathogenic to poplars established that for each species, holotype and herbarium
specimens of D. populorum, D. tremulae and
D. punctiformis were morphologically similar. Light and electron
microscope studies of
apothecia revealed that in radial longitudinal section, in apothecial
shape and the hypothecial and epithecial tissues of the three
species were similar. In general, ectal and medullary excipular tissues
of
D. populorum were more strongly developed than those of
D. tremulae and D. punctiformis. Asci and ascospores
of
D. populorum were larger than the other two species but because
of overlap
were of limited use for species delimitation. In consideration of the
established synonymy of the anamorphs of D. tremulae and
D. punctiformis namely, Marssonina tremulae and
M. brunnea, respectively, and close morphological similarity of
their teleomorphs,
synonymy of D. tremulae and D. punctiformis is
suggested, with D. tremulae having priority. Although not studied,
D. populi-albae is believed to be a distinct species. Accordingly,
three Drepanopeziza holomorphs are recognised on poplars:
D. populi-albae, anamorph=M. castagenei; D. populorum
anamorph=M. populi; and D. tremulae, anamorph=M.
brunnea.