Notes: Two rust fungi with cupulate aecia on Agathis spp., formerly placed in the form-genus Aecidium, belong here. Our analyses consistently place these in a lineage separate from all other sequenced Pucciniales (Fig. 1). Despite over a decade of sampling rust fungi from Australia and Southeast Asia on hosts co-distributed with Agathis species, we have been unable to locate a telial state for these rusts. Peterson (1968) ruled out the possibility that Araucariomyces represents an endocyclic form, because aeciospores of Ar. balansae germinate to produce germ tubes rather than basidia. As is conjectured with Rogerpetersonia, the life cycle may not produce a sporothallus, and instead has adapted to systemically infect their hosts possibly including a cryptic sexual or parasexual cycle.