Dryopteris cristata × D. carthusiana
(D. × uliginosa (A. Braun ex Döll) Kuntze ex Druce), a hybrid
Buckler-fern
Account Summary
Very rare, but a definite error here.
1860; Smith, Rev Prof R.W.; "From the vicinity of Brookeborough".
This very rare hybrid was again recorded from the same site as the species above, the station being vaguely described and reported by Smith in his 1860 paper in the Natural History Review 7(2): 40. Again, as in the case of Dryopteris submontana (Rigid Buckler-fern), with hindsight, Smith was certainly mistaken. Rev Prof Smith was a foremost British fern expert and the first discoverer of many of Fermanagh's ferns, and while he did make a few errors, the fern taxonomy of his day was very different from ours. We must not lose sight of that significant fact and make unjust criticism of his mistakes.
The plant would much more likely to have been D. × deweveri (ie D. carthusiana × D. dilatata), since both of these parent species occur in Co Fermanagh, and the hybrid between them rarely occurs or is rarely reported elsewhere in Ireland. D. cristata (Crested Buckler-fern), on the other hand, is totally unknown anywhere on the whole island of Ireland (Meikle et al. 1975 Revised Typescript Flora). Regrettably we do not have any other records of D. × deweveri in the Fermanagh Flora Database to support this suggestion. The New Atlas and New Fern Atlas hectad map of D. × deweveri plots a total of just ten symbols of any date for Ireland, so this hybrid is also very clearly seriously under-recorded on the island (T.D. Dines, in: Preston et al. 2002; Wardlaw & Leonard 2005).
Growth form and preferred habitats
A medium-sized, finely-divided, stiff, upright-fronded, deciduous Buckler-fern with a distinctive dull, greyish-green, mealy surface, this is a rare plant of base-rich rocks, including deep crevices (grikes) in limestone pavement, coarse limestone screes (block screes) and rock crevices where moist, humus-rich, peaty soils develop. D. submontana prefers a degree of shelter from weather and adequate protection from grazing is essential to its survival, but is intolerant of all but light shade. It therefore tends to occur in relatively inaccessible places, such as rock ledges, deeper, wider grikes in limestone pavement and amid thorny or evergreen scrub that provides shelter and protection.
British Isles occurrence
This is a rare plant confined to a limited area of limestone terrain in the northern English Pennines, although there are also rare outlying stations in N Wales and the NW Midlands.
Fermanagh occurrence
This fern, of which there is just the solitary record listed above, was recorded at the time as Lastrea rigidum (= L. rigida (Sw.) C. Presl). However, it must certainly be wrongly identified, since this very rare, deciduous, calcicole species which demands sheltered, moist, humus-rich soils, has never been found anywhere else in Ireland. Neither Meikle and his co-workers (who in 1957 and 1975 referred to the plant as Dryopteris villarii (Bell.) Woynar), nor we, can identify what fern might have been taken for this in error by an expert pteridologist like Rev Prof Smith.