Polystichum setiferum × P. aculeatum
(P. × bicknellii (H. Christ) Hahne), a hybrid Buckler-fern

Account Summary

Growth form and appearance

P. × bicknellii is evergreen and calcicole like its P. setiferum (Soft Shield-fern) parent and it can be distinguished by the presence of mostly abortive spores. The plant closely resembles a large, leathery, robust, dark green form of P. setiferum.

Fermanagh occurrence

This hybrid has been found only once in Fermanagh as detailed above, but it should be looked for in shaded, mainly lowland areas where both parent ferns occur (Northridge et al. 1988). Apart from the limestones of the Western Plateau, the Florencecourt and Maguiresbridge areas and the ground lying north of Kesh are the main localities in Fermanagh where both parents commonly meet and this sporadically occurring hybrid is most likely to occur.

British and Irish occurrence

Throughout Britain and Ireland, this hybrid occurs thinly scattered as isolated individuals, mainly in ecologically open, calcareous or base-rich soils. Typical habitats include rocky woodlands, limestone gorges, stream banks and old disused quarries. It seems particularly associated with ground where both parents are involved in recolonisation after disturbance (Jermy et al. 1978). The hybrid is very easily overlooked, and Page (1997) therefore believes it is under-recorded.

Threats

None.

• Find out more about the format of the species accounts
• View abbreviations
• View references for all species accounts
• View a gazetteer of all the sites