Species concepts in the Cylindrocladium floridanum and Cy. spathiphylli complexes (Hypocreaceae) based on multi-allelic sequence data, sexual compatibility and morphology

Much attention has recently been devoted to the delimitation of species uni ts in Cylindrocladium (Cy.). In this regard the present study focuses on th e taxa within the unresolved Cy. floridanum and Cy. spathiphylli species co mplexes. Maximum parsimony analyses of DNA sequences of ITS, P-tubulin and histone regions of rRNA genes, and mating experiments revealed a geographic ally isolated species of Cylindrocladium in the Cy. spathiphylli (teleomorp h: Calonectria spathiphylli) species complex. Cy. pseudospathiphylli sp. no v. (teleomorph: Ca. pseudospathiphylli sp. nov.) is described as a new phyl ogeneric, biological and morphological species. It is distinguished from Cy . spathiphylli by being homothallic, having smaller macroconidia, and disti nct DNA sequences of beta -tubulin and historic genes. Similarly, parsimony analysis of a combined data set also indicated several phylogenetic specie s to exist within Cy. floridanum (teleomorph: Ca. kyotensis). Based on diff erences in vesicle morphology and conidium dimensions, the Canadian populat ion of Cy. floridanum, formerly known as Cy. floridanum Group 2, is describ ed as Cy. canadense sp. nov., while a further collection from Hawaii is des cribed as Cy. pacificum sp. nov.