Nation's botanical treasure troves 'under huge threat'

A million plants from every corner of the globe are tucked away inside the cabinets that line the walls.

It's a scientific collection that goes back centuries, gathered by the likes of Carl Linnaeus, the "father of taxonomy", and Charles Darwin.

They could have had no inkling that pressed, dried collections of plants would have modern uses in assessing extinction risks.

Estimates suggest one in five of the world's plant species is threatened.

Collections of pressed, dried plants are an important "living" resource, say scientists.