Ascocarp development of Eutypella parasitica
Perithecial initials of Eutypella parasitica were found during the spring in bark phellem of cankered sugar maples. These initials were commonly intermingled with mature perithecia probably produced in the current year. One or several ascogonial coils appeared in these initials, but no trichogyne-like hyphae were seen in the archicarp. Asci developed rapidly from croziers formed on ascogenous hyphae and enlarged almost to their mature size before the diploid fusion nucleus divided to form the eight ascospores. The perithecium of E. parasitica has a Xylaria-type centrum as defined by Luttrell in 1951.