Pomaderris apetala subsp. apetala is endemic to Australia where it ranges from eastern Victoria south to Tasmania. It's range there overlaps somewhat with subsp. maritima in Tasmania. Pomaderris apetala subsp. maritima is indigenous to both Australia and New Zealand. A detailed explanation about these two subspecies can be found in Threatened Plants of New Zealand published by the University of Canterbury Press. Although there appears to be no significant differences between New Zealand and Australia populations of subsp. maritima, P. apetala "type plants" have been in New Zealand since at least the Oligocene (based on fossil pollen and macrofossil evidence).
In New Zealand Pomaderris apetala subsp. maritima is frequently confused with Pomaderris aspera (of which we have a fact sheet). Pomaderris aspera is a somewhat similar species which has naturalised here.
Peter de Lange