Oaks (Quercus spp.) parasitised by mistletoe Viscum album (Santalaceae) in Britain

Abstract

Information on oaks Quercus spp. parasitised by Viscum album L. in Britain that was obtained in a comprehensive review of the literature and records with site visits from 1996 to 1998 has been updated during 2017 and 2018. Currently there are thirteen confirmed mistletoe-oaks in Britain. V. album parasitising Quercus spp. mainly occurs at locations in and around Herefordshire in the core of the current and past distribution of V. album in Britain. The results of this recent survey accord with the earlier review and with reports in the 19th and early 20th centuries suggesting that the population of between ten and twenty Quercus trees parasitised by V. album in Britain appears to be relatively stable over time with some losses of host trees and gains from the parasitism of new trees. Quercus robur L. is the most frequent host amongst the existing mistletoe-oaks which also include ‘red oaks’ (Q. rubra L., Q. coccinea Münchh. and Q. palustris Münchh.). The estimated ages of the existing Quercus hosts range from 30 to 400 years. The mistletoe-oaks are located in woodland, woodland edges, hedges, parkland, a garden, a churchyard and open countryside by a watercourse.