Yorkshire Feather Moss
Latin name: Thamnobryum cataractarum
This species of aquatic moss was new to science in 1991. It was discovered by bryologists Hodgetts and Blockeel on gritstone rock in a deep ravine near Ingleton in the Yorkshire Dales National Park. Research has shown that it is most closely related to Thamnobryum fernandesii, a moss that is endemic to Madeira.
In 2005, comprehensive survey work was carried out at the one known site to determine the true status of this species. Although the discovery site is a difficult area to survey, the moss was found at the majority of locations where it was possible to access the river. The results of this survey showed that Yorkshire feather moss is frequent along a just one 1km stretch of river.
No specimens of Yorkshire feather moss were found at any location outside of the ravine. Whilst there may be some undiscovered locations where this species grows, it is looking increasingly likely that this species is endemic to the Yorkshire Dales National Park.
Due to its rarity, Yorkshire feather moss is a UKBAP priority species and on the nature in the Dales 2020 Vision: the second biodiversity action plan for the Yorkshire Dales National Park. As a result a dedicated Dales Volunteer carried out non-destructive indirect monitoring twice a year.