World's highest plants discovered 20,000 feet above sea level

Africa's tallest tree discovered towering on continent's highest mountain

Photographer snaps rare shot of 'ghost rainbow'

Ant colonies discovered farming their own fruit crops

Mysterious 'earthquake lights' captured over New Zealand

5 invasive species that may have won the war

3 reasons why you shouldn't lose hope

Alaska's bizarre 'Ice Monster' has everyone stumped

This featherless penguin wears a custom wetsuit

5 facts about Vieques' bioluminescent Mosquito Bay

Iconic Milwaukee conservatory ranks among America's most endangered places

A 'hidden' forest in the shape of a Celtic cross has emerged in Ireland