This was previously regarded as a single species genus but some authorities now regard H. paludosa as being within the same genus as Microstylis monophyllus and placed them both within the  genus Malaxis.  This is a widespread genus of some 182 species that may be found in both temperate and tropical area's of the world.

There are certainly close morphological similarities between the two species and together with Liparis loeselii they are the only true European epiphytic orchids.

The species are largely thought to be pollinated by small insects and the seed that is produced can float in water. Its by this means that the species spreads most widely although uniquely among European orchids they can also propgate vegetatively via the production of bulbils that form at the tips of the leaves. These drop into the sphagnum and can develop very quickly.