Phylogenetic data for the lichen genus Bacidia originally used to describe a new species, Bacidia gigantensis

<p><i>Bacidia gigantensis</i>, a green to greenish-brown, sorediate, crustose to microsquamulose lichen is described a new to science. It is corticolous on mature <i>Thuja occidentalis</i> trees throughout Sleeping Giant Provincial Park on the Sibley Peninsula along the north shore of Lake Superior, Ontario. The species is unusual within <i>Bacidia</i> due to the production of asexual propagules and homosekikaic acid. Placement in <i>Bacidia</i> is based on the characters of the sexual reproductive structures (biatorine apothecia with a true exciple, <i>Bacidia</i>-type asci, sigmoid, acicular, ascospores), ITS sequence data and molecular phylogenetic analyses of mtSSU sequence data. The latter also inferred a relationship to <i>Bacidiopsora</i>, a tropical genus that has been proposed for synonymy with <i>Bacidia</i> and includes other species with similar chemistries.</p>