It was circumscribed by mycologists Otto Miettinen and Leif Ryvarden in 2016, as a continuation of prior work that outlined a revised framework for the Steccherinaceae based on molecular phylogenetics.
[1] Its closest relative in the Steccherinaceae is the genus Nigroporus, from which it differs in its light-coloured fruit bodies and monomitic context.
Microscopic characteristics of the genus include spores that are curved and cylindrical, cyanophilic skeletal hyphae (staining blue if the microscopic stain Lactophenol Cotton Blue is applied) and slightly thick-walled, wide generative hyphae in the context.
[2] Trulla contains six species that were transferred from various other polypore genera, including Antrodiella, Polyporus, Leptoporus, Coriolus, and Tyromyces.
[2] Most species of Trulla are found in tropical areas, although in some cases the distribution extends to south temperate regions in North America and Asia.