The Lacustromyces clade is the smallest of the newly identified clades with only three representative genera, two of which are inoperculate (Lacustromyces, Polychytrium). Though data has been published for only one species of Lacustromyces, unpublished observations of the zoospores of Karlingiomyces and Polychytrium give an indication of their having similar ultrastructural characters as found in Lacustromyces. The zoospore subtype for the group is designated as the Lacustromyces subtype in which all three have the same kind of primary rootlet: an irregular group of microtubules arising between a set of triplets with projections extending to the plasma membrane.