Ulmus plotii Druce, Plot's Elm
Account Summary
Introduced, neophyte, deliberately planted, very rare, although possibly under-recorded, now locally extinct.
1912; Druce, Dr G.C.; roadside hedges between Enniskillen and Dromore Td.
There is only one field record for this species in the Fermanagh Flora Database, but since it was recorded by G. Claridge Druce on a 'motor journey' through the county (Druce 1912), on which he probably was accompanied by Praeger, we feel it is worthy of mention. The rather vague site is absolutely typical of the time, being given only as, "Between Enniskillen and Dromore, Co. Fermanagh."
U. plotii is an endemic species of hedgerows in the English southern midlands, although it was declining even before the current Dutch Elm disease pandemic developed (C.A. Stace, in: Preston et al. 2002). Like U. minor (Small-leaved Elm) it is particularly susceptible to the more virulent form of Dutch Elm disease that arrived in England in 1967 with a cargo of timber from N America.
We believe Plot's elm is extinct in Fermanagh, but we freely admit that all the small-leaved elms would have repaid more time spent on them before the disease more or less wiped them out. The New Atlas map shows no records at all of U. plotii in Ireland, so this interesting old published record must have been overlooked.
Fermanagh occurrence
It seems rather strange that there were no records for this tree species before 1986 and that there have been quite so many records since. The Fermanagh Flora Database currently contains records from 73 tetrads (13.8% of those in the VC). On this basis, English Elm appears to be widely spread across the lowlands in woods along lakeshores and riverbanks, in field hedges and those along roadsides. Nevertheless, for reasons already mentioned in the U. glabra account above, the true identity of Fermanagh's planted elms undoubtedly requires further, more critical investigation. This is particularly the case for those forms of elm with small leaves, ie U. procera, U. minor (Small-leaved Elm), plus the rare or almost unrecorded U. plotii (Plot's Elm) and the hybrid U. × hollandica (Dutch Elm) – all of which have at least a few Fermanagh records (New Flora of the BI; Cat Alien Pl Ir). However, it must be remembered that the majority of these trees, if not quite all of them, have subsequently fallen victim to Dutch Elm disease and died, rendering their identity a purely academic question.
Dutch Elm disease
Even those elms which sucker and manage to re-grow after an attack by the fungus has killed off the mature stem, tend to succumb to secondary assaults of the disease when they get to a stem size of around 5 cm diameter. As a result they do not get the chance to flower and fruit and, furthermore, the normal leaf dimensions and other required identification characters are generally absent (Flora of Co Dublin; Pilcher & Hall 2001). It is also the case that, as with all other suckering species, leaves on suckers, or on epicormic side shoots are extremely variable and they provide totally unreliable features for identification purposes. Thus while some elm suckers do survive in hedgerows, they really have become impossible to properly identify (Stace 1997, 2010; Parnell & Curtis 2012).
Threats
Dutch elm disease has or will destroy most, if not all of these trees.