Biological Flora of Britain and Ireland: Viscum album: No. 303. (30th November 2022)

• Record Type: Journal Article
• Authors: Thomas, Peter A.; Dering, Monika; Giertych, Marian J.; Iszkuło, Grzegorz; Tomaszewski, Dominik; Briggs, Jonathan
• Is Part Of: Journal of ecology. Volume 111:Number 3(2023)
• Page Start: 701
• Page End: 739
• Publication Date: 2022-11-30
• Subjects: climatic limitation -- ecophysiology -- geographical and altitudinal distribution -- germination -- herbivory -- plant hemiparasite -- reproductive biology; Plant ecology -- Periodicals; 577.05
• DOI: 10.1111/1365-2745.14036
• Languages: English
• ISSNs: 0022-0477

Abstract

Abstract: This account presents information on all aspects of the biology of Viscum album L. (Mistletoe) that are relevant to understanding its ecological characteristics and behaviour. The main topics are presented within the standard framework of the Biological Flora of Britain and Ireland : distribution, habitat, communities, responses to biotic factors, responses to environment, structure and physiology, phenology, floral and seed characters, herbivores and disease, history, and conservation. Viscum album is a widespread obligate hemiparasite on a wide range of angiosperm and gymnosperm trees. Once thought to take just water and nutrients from its host via a haustorium, it is now suggested to also take carbon. Heavy infestations can reduce host vitality through prolific water use and carbon removal. Flowers are highly reduced but are primarily pollinated by flies, ants and bees. Seeds are dispersed by birds. Removal of the epicarp is necessary for successful seedling establishment, and seeds have a sticky viscin coat, adhering it to the host bark. Vegetative spread also happens under the bark of its host resulting in densities of >700 Mistletoe plants per host. Viscum album is a lowland species, most frequent in open human‐made habitats extending into woodlands in Europe. It has been widely planted for folklore use centred around Christmas. Despite conservation concerns following removal of Mistletoe‐laden old orchards, the species is thriving and needs control in some areas. Viscotoxins and lectins in leaves and shoots have been widely used in herbal medicine and now potentially in complementary cancer therapy. Abstract : Mistletoe is a charismatic parasite of tree crowns with a long history of folklore and connections with Christmas celebrations. This, and its need for light, helps explain why it is most common in human‐made habitats across Europe. Once thought to benignly take just water and nutrients from its host it is now known to take carbon as well which can lead to loss of vitality in its host. Seeds have a sticky viscin coat that helps ensure that as bird dispersers excrete them or wipe them from their beak, they stick to the bark of a host, ideally placed for germination.