Hollow of the Milktree

Explanation: What are we viewing here? I have jammed myself through a small opening in the trunk of a large tree, in the dead of the night, to take this flash photo pointing upwards ... to my surprise, discovering that this tree seems to be completely hollow at least half way up.

We are in a very remote corner of the Garo Hills in far western Meghalaya state, in northeast India. It was several days' journey to get here from Delhi by way of airplane, 4 wheel-drive jeep, a river barge/ferry, and more 4-wheel driving, to hike into this forest conservation grove near the settlement of Williamnagar. I am here on a wildlife study of the region, accompanied by a team of other researchers and local Garos.

This tree, though, is a remarkable regional endemic. Milktrees are so-named because, as a euphorb, they produce the milky fluid latext which is a complex of gums, sugars, oils, proteins, alkaloids, and other constituents. Biochemical studies of this particular milktree species have shown that the leaves contain chemicals that might have antitumor, antimicrobial, and pesticidal uses (Ahmed et al. 2010). Other studies suggest that the alkaloid known as bukittinggine, also from this tree, can serve as an anti-inflammatory, an analgesic, and an antipyretic (Panthong et al. 1998). Further, other sources suggest that the species is used widely for timber; that it bears sweet, edible fruits; and that it has been used in Malaysia to treat ulcers.

But back to this particular tree. Such hollow trees in this part of India can serve as roost sites for many species of bats, and den sites for more dangerous creatures such as sloth bears and even tigers. This tree was empty, at least to the moment, to my disappointment but perhaps also to my good luck ...

And a final word on taxonomy. There is some confusion over the scientific placement of this species in its botanical family. Some sources refer to Sapium baccatum as being found mostly or only in southeast Asia and not India, whereas my local botanist colleague asserted that it indeed is found in northeast India where we were.

The milktree with the hollow core ... along with the team
of researchers and local Garo Hills villagers.

Information:
     Ahmed, Y., M.H. Sohrab, S.M. Al-Reza, F.S. Tareq, C.M. Hasan, and M.A. Sattar. 2010. Antimicrobial and cytotoxic constituents from leaves of Sapium baccatum. Food and Chemical Toxicology 48:549-552.
     Panthong, A., K. Kanjanapothi, Y. Thitiponpunt, T. Taesotikul, and D. Arbain. 1998. Anti-inflammatory activity of the alkaloid bukittinggine from Sapium baccatum. Planta Medica 64(6):530-535.
     Ramadhan Al Muqarrabun, L.M., N. Ahmat, S.R.S. Aris, N. Norizan, N. Shamsulrijal, F.Z.M. Yusof, M.N. Suratman, M.I.M. Yusof, and F. Salim. 2014. A new triterpenoid from Sapium baccatum (Euphorbiaceae). Natural Product Research http://dx.doi.org/10.1080/14786419.2014.903396

EPOW - Ecology Picture of the Week