Isolates Intermediate Between Stachybotrys and Memnoniella

Abstract

Isolates of an intermediate nature between Memnoniella von Höhnel and Stachybotrys Corda have been observed. Stachybotrys-like slimy heads of elliptical to oval spores and Memnoniella-like heads of chains of spherical spores can occur on separate phialophores on the same hypha, or separately on the two phialophores of a branched phialophore. Single-spore isolates of cultures exhibiting this phenomenon continue to do so, whether the single spore is of the elliptical Stachybotrys type or of the spherical Memnoniella type. Isolates stable for the characters of Memnoniella echinata for eight years are also reported. The form genera Memnoniella and Stachybotrys are considered to be valid entities.