A team of British and Chinese biologists has discovered three new species of nettles in China, one in a cave and another two in deep gorges.
South West China, Myanmar and Northern Vietnam contain one of the oldest exposed outcrops of limestone in the world. Within this area are thousands of caves and gorges. It is only recently that botanists have sought to explore the caves for plants.
The current study, published in the journal PhytoKeys, describes three new nettle species named: Pilea cavernicola, P. shizongensis and P. guizhouensis.
These species belong a genus of nettles known as Pilea that is believed to have over 700 species worldwide, up to one third of which may remain undescribed.
The cave-dwelling nettle species P. cavernicola was found growing in two caves in the Guangxi province of China.
P. guizhouensis is known from an unusual and striking rock mineral formation called petaloid travertine. Petaloid travertine is a form of limestone deposited by mineral springs that over time forms large petals of rock, in this case clinging to the vertical walls of a gorge.
“When my Chinese colleague Wei Yi-Gang from the Guangxi Institute of Botany first mentioned cave-dwelling plants to me, I thought that he was mis-translating a Chinese word into English. When we stepped into our first cave, Yangzi cave, I was spell-bound. It had an eerie moonscape look to it and all I could see were clumps of plants in the nettle family growing in very dark condition,” said study lead author Dr Alex Monro of the Natural History Museum in London and the Royal Botanic Gardens, Kew.
The plants do not grow in complete darkness but do grow in extremely low light levels, deep within the entrance caverns of the caves, sometimes, in as little as 0.04% full sunlight.
Bibliographic information: Monro AK et al. 2012. Three new species of Pilea (Urticaceae) from limestone karst in China. PhytoKeys 19: 51–66; doi: 10.3897/phytokeys.19.3968