The species was introduced as Heterochaetella brachyspora by Luck-Allen (1960) with the type specimen collected in France and labelled by Bourdot as Heterochaetella dubia var. mesochaeta f. brachyspora. However, Luck-Allen’s idea about spore shape and size as the main diagnostic features of this species cannot be maintained. After re-studying the isotype of H. brachyspora, we concluded that it is identical with specimens collected from coniferous wood throughout the northern hemisphere. Those collections (of which six were sequenced) show the widest spore variation range within the genus. However, they can undoubtedly be addressed to this species due to other morphological features, i.e., clearly gelatinized and rather thick basidiocarps and apically very thin-walled and often collapsing, fragile tramal cystidia. Protomerulius brachysporus is the only conifer-dwelling species so far recognized in the genus. This host preference helps in identification of juvenile specimens possessing thinner basidiocarps and smaller basidiospores which otherwise can be mixed up with other effused non-poroid representatives of the genus.