Out of Africa? New bamboo genera, mountain gorillas, and the origins of China’s bamboos

20130824-062547.jpg

Caption: Young Mountain Gorilla inspects shoot of Oldeania alpina
Credit: Kate Tann 2012

Hidden away on mountains in the tropics where they provide food for gorillas, just as China’s bamboos provide food for the Giant Panda, are the only two species of African mountain bamboos.

They are something of a mystery, as nearly all bamboos are found in Asia or South America.  It was thought that they were very closely related to Asian bamboos, but their respective ranges are separated by thousands of miles.

As flowering in bamboos is a rare event, seed dispersal takes a very long time, and the suspicion arose that they might be old enough to represent new genera, and possibly could even be remnants of the earliest temperate bamboos, which spread to Asia on drifting tectonic plates.

Dr Chris Stapleton, who has studied Himalayan bamboos, turned his attention to the bamboos of Africa. He found that the features of the mountain bamboos were significantly different to those of Asia, and together with the large geographic separation, the differences were sufficient for the recognition of these two new African genera, now named BergbambosandOldeania,after their local names in the Afrikaans and Maasai languages. The species are now Bergbambos tessellata and Oldeania alpina

DNA results show that the African bamboos represent two separate lineages, and neither can be included in any known Asian genus.

Earlier work on the global distribution of bamboos has shown that bamboos evolved in the southern hemisphere on a landmass called Gondwanaland, parts of which spread apart to form South America, Africa and Asia when it broke up as a result of continental drift, the slow movement of tectonic plates on the earth’s surface.

The incredible variety of temperate bamboos in China is thought to be a result of the early bamboos spreading out from either Africa or India when the plates collided and allowed the hitch-hiking bamboos to jump across into new territory.

20130824-064345.jpg

Bergbambos tessellata is a clump-forming bamboo with ragged leaves and sheaths found in dry areas of southern Africa especially the Drakensberg Mountains.
Credit: Chris Stapleton

The features and DNA of the African bamboos are certainly different to those of East Asia, but it is still not clear whether they are really different enough to represent ancestors of all the Asian bamboos.

It will be necessary to hunt out and study mountain bamboos of Sri Lanka and Madagascar and to include them in a broader analysis. From this review, however, it looks as though African bamboos evolved about the same time as the bamboos of E Asia.

The myriad temperate bamboos of China are more likely to have been a gift from India, rather than another ‘Out of Africa’ story, but further work is needed to be sure. What is clear is that Africa has two more endemic genera, and the bamboos are seen to be as unique as the animals that depend upon them.

20130824-064723.jpg

Oldeania alpina looks like a Phyllostachys species from China, but is very different under the ground and in its branching. It is found on mountains from Cameroon across to Ethiopia.
Credit: Drs Peter Gill & Eric Boa

Did you find this information helpful? If you did, consider donating.

About Editor

Anything posted by the editor comes straight out of a media release.