Isolation of Hypoxylon mammatum from aspen stem sections

Hypoxylon mammatum developed in noninoculated aspen stem sections which had the top ends dipped in paraffin and were then placed in moist sand, at 24C and 90% humidity for 3 months. The development of the fungus in the stem sections might have been due to the presence of ascospores or mycelium on or in the outer tissues of the stems.