Microscopical the genus Thuidium is easy to recognize, because each leaf cell has exactly one papilla. The leaves are more or less triangular with a heart-shaped base and long acuminate. They are very plicate and the strong midrib ends in the tip of the leaf.
Worldwide there are 200-240 species, which are spread over nearly the whole earth. In europe there are only 4 species.
Thuidium tamariscinum is a moss, which is remarkable by its very regularly double or triple pinnate ramification. The cells at the tips of the branch leaves of this species have only one pointed papilla, whereas the tip-cells of the other species of the genus have several papilla, so that the branch leaves seem to be multifid. Under the european Thuidium species Th.tamariscinum is the most frequent and the most robust. Beacause of its remarkable regular ramification and the triangular form of the fronds the species is sometimes used as "conifer" for model railways.
In europe the species is rather frequent in all kinds of forests, on the ground, e.g. beside forest paths, and is an indicator for good, mineral rich soils.