This plant grows on one site only on our 50 hectare property - on a south facing slope that is lightly treed with Iron bark, Stringy bark and broad leaved peppermint gum leaves. Used to occur higher up the slope than it does now.
Since this is in undisturbed bushland, I think the ID of Ajuga australis is OK. The overall look of the plant is not that typical. On more disturbed sites, Prunella vulgaris is superficially similar.