Colin Varndell / Mistletoe (VIscum album) berries. Somerset, UK, November.

Colin Varndell / Mistletoe (Viscum album) growing on apple tree. Somerset, UK November

Fabrice Cahez / Mistle thrush (Turdus viscivorus) perched next to Mistletoe (Viscum album) in winter, Vosges, France, January

Rolf Nussbaumer / Northern mockingbird (Mimus polyglottos) adult eating ice covered Christmas mistletoe berries (Phoradendron tomentosum) Dinero, Lake Corpus Christi, South Texas, USA.

Rolf Nussbaumer / Green jay (Cyanocorax yncas) adult perched on ice covered Christmas mistletoe (Phoradendron tomentosum) Dinero, Lake Corpus Christi, South Texas, USA.

Gary K. Smith / Mistletoe (Viscum album) seed deposited by bird on apple tree, showing embryo roots attached to bark. Norfolk, England, April.

Philippe Clement / Mistletoe (Viscum album) infestation on tree in spring. La Brenne, France, April.

Nick Upton / Mistletoe (Viscum album) male plant growing on an apple tree (Malus domesticus) in evening light, Brandenburg, Germany, April.

Philippe Clement / European Mistletoe (Viscum album) close-up of branch of male, Luxembourg

Mark Bowler / Mistletoe (Viscum album) twig with two berries

Roger Powell / Red-berried southern Mistletoe {Viscum coloratum} growing on host tree of Portuguese Oak (Quercus faginae) Sierra de Grazalema, Andalusia, Spain

Gary K. Smith / Mistletoe (Viscum album) with ripe white berries on old apple tree, Norfolk, England, UK, December

Gary K. Smith / Mistletoe (Viscum album) high on Common Lime tree (Tilia vulgaris), Norfolk, England, UK, October

Gary K. Smith / Mistletoe (Viscum album) high on Common Lime tree (Tilia vulgaris), Norfolk, England, UK, October

Christoph Becker / Mistletoe {Viscum album} Germany

Philippe Clement / Juniper mistletoe (Phoradendron juniperinum). Grand Canyon National Park, Arizona, USA

Philippe Clement / Mistletoe (Viscum album) in Poplar tree (Populus sp) tree. La Brenne, France

Philippe Clement / Mistletoe (Viscum album) in Poplar tree (Populus sp) La Brenne, France

Philippe Clement / Mistletoe (Viscum album) in Poplar trees (Populus sp) La Brenne, France 2007

Philippe Clement / Mistletoe (Viscum album) in Poplar trees (Populus sp) La Brenne, France

Philippe Clement / Mistletoe (Viscum album) in Poplar tree (Populus sp) La Brenne, France

Yuri Shibnev / Mistletoe berries {Viscum coloratum} Ussuriland, Primorskiy, Far East Russia

Yuri Shibnev / Mistletoe berries {Viscum coloratum} Ussuriland, Primorskiy, Far East Russia

Martin Gabriel / Mistletoe {Viscum album} in Birch tree {Betula pendula} Bavaria, Germany

Niall Benvie / Mistletoe berries {Viscum album} against Poplar bark Bialowieza NP, Poland

Albert Aanensen / Box mistletoe flowers {Amyema miquelli} New Zealand

Michael Quinton / Common Porcupine (Erethizon dorsatum) feeding on Mistletoe (Phoradendron serotinum) in winter, Island Park, Idaho

Kim Taylor / Mistletoe (Viscum album) with berries in winter. Surrey, UK