Naiadella fluitans gen. et sp. nov.: a conidial basidiomycete

Naiadella fluitans Marvanová & Bandoni, gen. et sp. nov. (Moniliales) was isolated from Scirpus microcarpus leaf litter collected in Vancouver, Canada, and from foam in Czechoslovakia. The genus is characterized by (1) dikaryotic hyphae with clamps; (2) serially arranged monoblastic conidiogenous cells, the protoplasmic content of each of which is transferred to a single conidium; (3) binucleate fusoid conidia with 3-4 bristle-like branches typically near the distal end; (4) germination of conidia by a germ tube, the conidial protoplast moving into the tube; (5) the presence of binucleate cells which we interpret as haustorial branches similar to those in mycoparasitic Tremellas.