The genus Hyphodontia is reviewed for southern Argentina from specimens gat
hered on Nothofagus spp., Austrocedrus chilensis, Drymis winteri, Maytenus
magellanica and Berberis ilicifolia. Sixteen species are reported, five of
which are new taxa, namely, Hyphodontia crassisipora, H. gamundiae, N. hjor
tstamii, H. magnifica and H. pumilia. A new name and new combinations are p
roposed for names of species not found in the area but similar to some of t
he described taxa: Hyphodontia cunninghamii nom. nov., H. subscopinella com
b. nov. and N. rickii comb. nov. Several of the new taxa have thick-walled
spores that may be cyanophilous and metachromatic. These characters, typica
l of the genus Hypochnicium, are shown to fit within Hyphodontia, given oth
er morphological features typical of the genus, i.e., hyphal features, basi
diome construction, and morphology of cystidia and basidia. A dichotomous k
ey to the sixteen taxa in Patagonia is provided.