Esslinger, Brodo, and MO all support Heterodermia leucomela, though Heterodermia leucomelos does seem to be current in Species Fungorum. Also, Esslinger doesn't recognize subspecies.
Esslinger, T. L. 2014. A cumulative checklist for the lichen-forming, lichenicolous and allied fungi of the continental United States and Canada. North Dakota
State University: http://www.ndsu.edu/pubweb/~esslinge/chcklst/chcklst7.htm (First
Posted 1 December 1997, Most Recent Version (#19) 23 March 2014), Fargo, North Dakota. (Link)
Unintended disagreements occur when a parent (B) is
thinned by swapping a child (E) to another part of the
taxonomic tree, resulting in existing IDs of the parent being interpreted
as disagreements with existing IDs of the swapped child.
Identification
ID 2 of taxon E will be an unintended disagreement with ID 1 of taxon B after the taxon swap
If thinning a parent results in more than 10 unintended disagreements, you
should split the parent after swapping the child to replace existing IDs
of the parent (B) with IDs that don't disagree.
