Phylogenetic relationships of Sphaerophoraceae (Ascomycetes) inferred from SSU rDNA sequences

SSU rDNA was sequenced from the lichenized fungi Bunodophoron scrobiculatum and Leifidium tenerum (Sphaerophoraceae), and Stereocaulon ramulosum and Pilophorus acicularis (Stereocaulaceae) and analysed by maximum parsimony with 44 homologous ascomycete sequences in a cladistic study. A small insertion (c. 60 nt.) was found in the sequence of Leifidium tenerum. Sphaerophoraceae constitutes a strongly supported monophyletic group which groups together with Lecanora dispersa and the Stereocaulaceae. Together with Porpidia crustulata, this larger group is a sistergroup to the Peltigerineae. This analysis thus supports the Lecanorales as monophyletic, including Sphaerophoraceae and the Peltigerineae, but does not provide strong support for this monophyly. The analysis also suggests that the prototunicate ascus in the Sphaerophoraceae is a reversion to the plesiomorphic state. Based on morphological, anatomical and chemical reasons, Sphaerophoraceae is proposed to belong to one of the groups presently included in the paraphyletic suborder Cladoniineae within the Lecanorales.