Yukihiro Fukuda / Japanese macaque / Snow monkey {Macaca fuscata} male grooming female in courtship in Japanese green alder tree {Alnus firma}, autumn, Jigokudani, Nagano, Japan

Wild Wonders of Europe / Bartocha / Shuttlecock ferns (Matteuccia struthiopteris) and Black alder trres (Alnus glutinosa) in Ghimbavul Valley Gorge, Arges County, Leota Mountains range, Carpathian Mountains, Romania, July

Grzegorz Lesniewski / Green Alder (Alnus viridis) at Krzemien Peak. Bieszczady National Park, the Carpathians, Poland, May 2009.

Nick Upton / Black alder (Alnus glutinosa) swamp forest / carr woodland. Schorfheide-Chorin Biosphere reserve, Brandenburg, Germany

Nick Upton / Black alder (Alnus glutinosa) swamp forest / carr woodland, Schorfheide-Chorin Biosphere reserve, Brandenburg, Germany

Colin Varndell / Leaf of the Common alder tree (Alnus hirsuta) UK, May

Pete Cairns / Close-up of Common alder leaf {Alnus glutinosa}, Scotland, UK.

Yuri Shibnev / Alder leaves and fruit, Ussuriland, Primorsky region, Russia

Nigel Bean / Fern in Alder wood Dinas Hill RSPB reserve, Wales, UK