Tilia platyphyllos × T. cordata (T.
× europaea L., T. × vulgaris Hayne),
Common Lime

Introduced, deliberately planted, occasional, but very definitely deliberately ignored and under-recorded.

10 July 1986; Austin, L.W. & McMullin, A.S.; Upper Lough Erne shore near Knockninny Hill.

May to November.

The New Flora of the BI (1997) notes that this large deciduous hybrid is one of the commonest planted trees in Britain. The British tree expert Alan Mitchell (1996) describes it as, "an unfortunate and ill-favoured tree", since although it is a natural hybrid between two species of considerable arboricultural distinction, it has inherited only the bad features from each parent. The most obvious and very common defect is the presence of vigorous basal suckers and epicormic shoots emerging from burrs higher up the trunk. These disfiguring outgrowths are inherited from T. cordata (Small-leaved Lime), but on that tree species, they generally appear only on very old specimens.

Common Lime is thinly and widely scattered in Fermanagh, mainly on large estates and in the grounds of larger, older houses around both parts of Lough Erne, but it occasionally appears planted in roadside hedgerows, along river banks and on or near lake shorelines. It is very seriously under-recorded as there are only records of it from 16 widely scattered tetrads in the Fermanagh Flora Database, 3% of the squares in the VC. The majority of recorders working in Fermanagh entirely ignore planted aliens. Neither Praeger nor Meikle and his co-workers recorded trees much at all and we ourselves have not bothered greatly keeping records of obviously planted specimens. Thus the real distribution of this partially fertile hybrid tree and indeed all other alien tree species in the county, needs further concerted investigation.

Half of the Tilia records were originally listed as T. cordata largely or entirely on the basis of lower leaf and bud colour characters. Pigott (2003), however, points out that these are not satisfactory features for distinguishing mature trees. Reliable identification requires material from the exposed (generally upper) leaf canopy, preferably also with supporting flowers or fruit. Since older trees are often very large, obtaining such specimens is difficult or totally impossible. In view of this and of our experience of lime trees generally, we feel that none of the Fermanagh tree records is likely to be true T. cordata, but rather they very probably all belong to one of the two widespread clones of this hybrid. We have therefore judged it sensible to consolidate all the records into this taxon.

Common Lime has a rather irregular crown when compared to either of the parent species and this, and the extensive suckering and burring, is often sufficient to identify the hybrid and possibly the individual cultivated clone of it, even from a distance and in silhouette (see the excellent comparative figures in Pigott (1992)). Common Lime is widely planted across lowland areas of both B & I, although again, comparatively speaking, it is nothing like as frequent in the latter island (Preston et al. 2002).