ABSTRACT
Cleistothecia of Myxotrichum deflexum are composed of a lax network of peridial hyphae. Outer peridial hyphae (appendages) are very thick-walled and smooth; inner hyphae frequently terminate in spirals. Typical ascomycetous septa occur within the peridial hyphae. Asci develop by the crozier method. The ascus septum is provided with a dense pore coating similar to that described from a number of different ascomycete groups. Prior to ascospore delimitation, a typical ascus vesicle forms near the periphery of the ascus. This vesicle eventually invaginates to cut out eight navicular ascospores. Wall material forms between the two spore-delimiting membranes and consists of an inner light primary layer and an outer dense secondary layer.