Ultrastructure of the ascospore wall in Pezizales (Ascomycetes) — II. Pyronemataceae sensu Eckblad

The development of wall layers and ornamentation of ascospores is studied with the electron microscope in members of the Pyronemataceae. In all the species primary and secondary walls are formed successively. The primary wall appears to differentiate into two layers, an inner endospore and an outer epispore. The secondary wall is homogeneous in appearance and by redistribution and differentiation gives rise to patterns of ornamentation, which in Lamprospora crec’hqueraultii alone show an internal structure. The epiplasm appears to be involved in the formation of the secondary wall.