Hidden in the dark caves of southwest China, a fragment of Earth's last Ice Age might well survive. Sadly, there aren't any mammoths hiding out in there, but tiny plants might represent a last link to 30,000 years ago.

Researchers from the Chinese Academy of Science and the UK's Natural History Museum have identified seven species of nettle from the Guangxi and Yunnan provinces that are completely unlike the tropical vegetation that dominates the region. The nettles are only found in the darkest corners of the provinces' caves and gorges, places where barely any sunlight ever shines. In fact, some of the nettles have to survive on only 0.02% of total available sunlight - you don't find that level of darkness anywhere outside the ocean depths.
Natural History Museum researcher Alex Monro describes these unique plants:
"They grow at the backs of the main caverns in near-dark conditions. There must be something quite special about their photosynthesis. They probably activate the photosynthetic process very quickly, which enables them to take advantage of very short bursts of light, and they might go for slightly different wavelengths.
relics of a vegetation from a previous cooler climate that resembled that of the caves."
more
http://io9.com/5848009/the-ice-age-might-still-be-going-on-inside-chinas-deepest-caves