The genus Tubifera was revised by Leontyev et al. (2015). Based on DNA-sequence data and morphological characters a number of new species and a new subsp. in T. ferruginosa were described. The paper introduced two unusual features in myxomycetology: the use of the colour of the immature fructification as one of more characters defining a species, and the use the taxonomical level subsp., which has rarely, if ever, been used for myxomycetes.
As a consequence reports of T. ferruginosa from Denmark before 2015 must be considered as T. ferruginosa s.l. (in a broad sense). The two species keyed out below are known with certainty from Denmark, but more species are to be expected.
|1||Spores 7.1-8.1 µm in diam.; immature pseudoaethalia bright orange; tips of sporocarps adhering to each other||T. montana Leontyev, Schnittler & S.L. Stephenson|
|1'||Spores 6.4-7.3 µm in diam.; immature pseudoaethalia salmon to pink; tips of sporocarps free||T. ferruginosa (Batsch) J.F. Gmel.|