New Species of Oak Discovered in Thailand

Feb 13, 2014 by Sci-News.com

Chinese and Thai biologists say they have discovered a new stone oak species in Thailand.

Lithocarpus orbicarpus, a branch with leaves. Image credit: S. Sirimongkol / J. S. Strijk.

Lithocarpus orbicarpus, a branch with leaves. Image credit: S. Sirimongkol / J. S. Strijk.

More than 300 species of stone oak are known from eastern India to Japan and the eastern tip of Papua New Guinea.

The new species, named Lithocarpus orbicarpus, is a medium to small tree with simple leaves.

It can be easily distinguished by its spherical acorns covered with a dense pattern of irregularly placed scales that completely conceal the nut, except for a tiny opening at the top, and which are arranged in dense clusters on upright spikes.

Lithocarpus orbicarpus is currently known only from the Ton Pariwat Wildlife Sanctuary in Thailand.

Lithocarpus orbicarpus, young infructescences. Image credit: S. Sirimongkol / J. S. Strijk.

Lithocarpus orbicarpus, young infructescences. Image credit: S. Sirimongkol / J. S. Strijk.

This sanctuary is popular for its rich bird- and wildlife such as the Blue-banded Kingfisher and Whitehanded Gibbons, as well for its rare and beautiful flora like Rafflesia’s – known to hold some of the largest flowers on Earth. It covers a region of low-lying forested mountains and is located in the middle of a fascinating transition zone that lies between the northern Indochinese and the southern Sundaland biogeographic regions.

“During our field survey, we found only one individual tree, located on a gentle sloping section of closed dense forest,” said Dr Joeri Strijk from the Xishuangbanna Tropical Botanical Garden, China, who is the lead author of a paper describing the new species in the open-access journal PhytoKeys.

Lithocarpus orbicarpus. Left: young acorn, opened up to show dotted pattern of small depressions and surface structure of the umbo. Right: fresh fruit – top, side and bottom view. Image credit: S. Sirimongkol / J. S. Strijk.

Lithocarpus orbicarpus. Left: young acorn, opened up to show dotted pattern of small depressions and surface structure of the umbo. Right: fresh fruit – top, side and bottom view. Image credit: S. Sirimongkol / J. S. Strijk.

“We know next to nothing about this species’ biology, its evolution or position within the Oak family. Follow-up molecular work will provide us with more information, but additional survey work will have to be undertaken to determine the actual population size within the sanctuary.”

“So far, it seems that the species is not only endemic but also very rare within the confined area where it appears,” Dr Strijk concluded.

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Strijk JS et al. 2013. Lithocarpus orbicarpus (Fagaceae), a new species of Stone Oak from Phang Nga province, Thailand. PhytoKeys 34: 33–45; doi: 10.3897/phytokeys.34.6429