Chamaecyparis lawsoniana (A. Murray bis) Parl., Lawson's Cypress
Account Summary
Introduction, neophyte, very rare, but possibly over-looked.
15 October 1987; Waterman T.; lakeshore, Inish Rath Island, Upper Lough Erne.
There is just a solitary record of this commonly planted conifer in the Fermanagh Flora Database, made on a DOE field survey of Upper Lough Erne. It was probably self-sown on the lakeshore, but might have been deliberately planted to provide shelter for other saplings. This dark, funereal, shrubby evergreen tree is all too commonly planted in parks, gardens, churchyards and shelter-belts (Mitchell 1996). It grows very vigorously and in Britain and Ireland frequently regenerates from seed, plants quickly becoming naturalised on open habitats such as along banks, by walls, on woodland margins and lakeshores.
A native of NW America (eg California and Oregon), C. lawsoniana was first introduced to the British Isles in 1854 and is now represented in horticulture by a huge range of cultivars (Griffiths 1994). It is much less frequently planted in rural than in urban areas, but it is sometimes recommended for shelter-belts and for under-planting as a nurse species in conifer plantations.
Nowadays, Lawson's Cypress is increasingly widespread in the wild, but was not recorded as such until as late as 1958. It appears to be much less frequently recorded in unplanted sites in Ireland than it is in Britain (M.E. Braithwaite, in: Preston et al. 2002).
Fermanagh occurrence
This evergreen conifer is widely used in forestry plantations in Fermanagh, but it has only been recorded in the county on seven occasions as a naturalised escape from cultivation. The first case was growing on the margin of a cut-over bog and on the adjacent roadside at the site listed above. Two further examples of self-sown plants alongside forest tracks were noted by RHN & HJN at Tullykeeran Td, Pettigo Plateau, 4 October 2010 and Tullyvocady Td N of Derrin Mountain, 26 October 2010. Other sites include near Moysnaght, and in two places around the shores of Lough Vearty where RHN recorded in December 2010.
British and Irish occurrence
Elsewhere in these islands, Stace (1997) mentions P. contorta being self-sown from only two areas, Cardiganshire (VC 46) and the Scilly Isles (VC 1b), but clearly it does so also in Fermanagh. The New Atlas hectad map now shows that P. contorta has been quite frequently and widely recorded across both Britain and Ireland, but especially so in the N & W regions of both islands.
Between 1945 and 1980, the two forms of this species were the second most abundant trees planted in Britain and Ireland, being used in re-afforestation to raise the planting limit above 100 m, and to extend planting to deep peat soils. The Shore Pine (var. contorta) was first introduced to forestry by A.C. Forbes of the Irish Forest Service, who discovered it as a rogue growing among a batch of seed of Pseudotsuga menziesii (Douglas Fir) imported from western N America in about 1920. He noticed that this form made good strong plants, but later it was found that when grown in the very exposed sites to which they appeared to be ideally adapted, Shore Pine soon became bowed at the base, the effect of strong wind on their very rapidly growing young stems.
Subsequently this led to growth trials of the inland form of the species, var. latifolia (Engelmann) Critchfield (Lodgepole Pine), and it is this particular variety which today forms much of the maturing pine forest in plantations, especially in the wetter, cooler N & W parts of Britain and Ireland (Mitchell 1996).