[1] Sunsequent molecular phylogenetic analyses showed that Allocetraria forms a monophyletic group within the cetrarioid clade in the family Parmeliaceae.
[2][3][4] In 2017, Divakar and colleagues used a then-recently developed "temporal phylogenetic" approach to identify temporal bands for specific taxonomic ranks in the family Parmeliaceae, suggesting that groups of species that diverged within the time window of 29.45–32.55 million years ago represent genera.
They proposed to synonymize Allocetraria (and several other genera) with Cetraria, because the former group of species originated relatively recently and fell under the timeframe threshold for genus level.
[6] Arve Elvebakk and colleagues expressed a similar opinion, stating that they would "prefer a model of 13 imperfectly defined cetrarioid core genera in addition to ‘orphaned’ species, over an alternative of only two widely defined ones, as a starting point for further phylogenetic studies".
[7] Distinguishing features of the genus include a palisade plectenchymatous upper cortex, asci with a broad axial body, ascospores that are more or less spherical, and threadlike (filiform) pycnoconidia.