Gerry Ellis / Ama'u Fern (Sadleria sp) in lava field, Hawaii Volcanoes National Park, Hawaii

Rob Brown / New Zealand Red Pine (Dacrydium cupressinum) and Crown Ferns (Blechum discolor), Ruggedy Range, Rakiura National Park, New Zealand

Matthew Maran / Hard / Deer fern (Blechnum spicant) growing in forest, Ucluth Peninsular, Vancouver Island, Canada

Michael & Patricia Fogden / Tree Fern (Dicksonia sp) and ground cover of Crown Ferns (Blechnum discolor) in temperate rainforest, Stewart Island, New Zealand

Michael & Patricia Fogden / Tree Fern (Dicksonia sp) and ground cover of Crown Ferns (Blechnum discolor) in temperate rainforest, Stewart Island, New Zealand

Ross Hoddinott / Hard fern {Blechnum spicant} frond uncurling, Cornwall, UK. April

Ross Hoddinott / Hard fern {Blechnum spicant} frond uncurling, Cornwall, UK. April

Tim Laman / Fern (Blechnum orientale) growing in rainforest, Taveuni Island, Fiji - one frond with pink tips

Tim Laman / Fern (Blechnum orientale) growing in rainforest, Taveuni Island, Fiji. Frond with pink tips.

Tui De Roy / Batwing Fern (Histiopteris incisa), Gough Tree Fern (Blechnum palmiforme), and Island Cape Myrtle (Phylica arborea) on coastal plateau, Gough Island, South Atlantic

Tui De Roy / Gough Tree Fern (Blechnum palmiforme) clusters growing in waterlogged coastal plateau, Gough Island, South Atlantic

Nick Groves / Crown Fern (Blechnum discolor) in Rimu Forest, between Mason and Doughboy Bays, Stewart Island, New Zealand