An ascomycete belonging to the genus Guignardia with a Phyllosticta anamorp
h was frequently isolated from living leaves of several ericaceous plants.
Ecological study on assemblages of endophytes suggested that this fungus is
a dominant endophytic fungus of ericaceous plants. The Phyllosticta anamor
ph was morphologically similar to Phyllosticta capitalensis P. Henn., which
can be a pathogen of orchids. An authentic culture of P. capitalensis IFO
32914 (= CBS 226.77) produced an ascigerous stage on potato dextrose agar,
the morphology of which was identical to the Guignardia sp. from ericaceous
plants. Sequence data of the internal transcribed spacer regions of riboso
mal DNA (ITS1 and ITS2, including 5.8S rDNA) supported the identity of the
present fungus and P. capitalensis. Consequently, we describe this endophyt
ic ascomycete found from ericaceous plants as Guignardia endophyllicola sp.
nov., which has P. capitalensis as an anamorph. Previously known as a patho
gen of orchids, the fungus was revealed to exist widely as an endophyte wit
hin ericaceous plants.