In Tasmania, Physcomitrella is represented by a single species, P. patens subsp. readeri (previously P. readeri). P. patens is widely known in biological circles as a model system for studying bryophytes and the genome of this species was completely sequenced in 2006.

P. patens subsp. readeri is a small ephemeral plant mostly found in dense patches or scattered on drying mud around ponds and lakes.

The leaves are translucent green and has a thin nerve which reaches to at most three-quarters of the leaf length. The globular capsules are borne on short stalks and near the shoot apex.