Several molecular studies have demonstrated that species
traditionally assigned to the form genus Acremonium are polyphyletic, while
Acremonium sensu stricto is a central element of the Bionectriaceae
(Hypocreales). Based on phenotypic characters and molecular phylogenetic
analyses, two new Acremonium species, A. moniliforme and A.
dimorphosporum, are described. The former is related to Emericellopsis and is
characterized by cylindrical conidia, acicular phialides and abundant moniliform
hyphae. Acremonium dimorphosporum resembles Acremonium borodinense. It
produces cylindrical, smooth-walled and ellipsoidal, rough-walled conidia. The
new genus Brunneomyces is proposed based on three species, including B.
brunnescens (formerly A. brunnescens), B. europaeus and B. hominis. All of
them are characterized by brown hyphae, sympodial conidiophores and chains
of ovoidal to ellipsoidal conidia. Also, the proposed new species Chordomyces
albus is characterized by its light-coloured colonies, simple or branched
conidiophores, phialides with percurrent proliferations and cylindrical collarettes,
and ellipsoidal to cylindrical conidia. The combined analysis of the LSU, ITS,
RPB2 and TEF1-α loci supports the inclusion of B. brunnescens, B. europaeus,
B. hominis and C. albus in Plectosphaerellaceae.