Discelium nudum

HomeLearningSpecies FinderDiscelium nudum

Identification notes

Discelium nudum is a rare and fascinating species and is the only member of the Disceliaceae family. It typically grows on wet sloping unstable banks of acid clay derived from shale. Often there are few competitors in this specialised habitat. It survives as a persistent protonema with tough rhizoids that extend down at least 1cm into the substrate and have abundant unicellular tubers rich in starch. These germinate rapidly on exposure but are not long lived. It is likely that the combination of the fibrous rhizoid network and the specialised tubers enable the plant to survive periods of erosion due to frost and running water.

The species is dioicous and both male and female plants are minute and bud-like, being less than 1mm in size. The leaf cells are apparently devoid of chlorophyll. It would be almost impossible to find were it not for the fact that it fruits abundantly, with the capsules developing in the autumn and maturing the following spring. The subglobose capsules are almost horizontal and develop on a seta than can be up to 25mm long, and sometimes undulate. It is this forest of long setae apparently arising from bare soil which attracts the eye. On close inspection the gametophyte plants become evident.

Read the Field Guide account

Distribution in Great Britain and Ireland

The stronghold of this species is in the Pennines, but there have been records from reservoir margins and china clay works.

View distribution from the BBS Atlas 2014