Rengas-attack

Another itchy and sleep-less week, this time not of the ticks but the notorious Rengas, a plant in the mango family (Anacardiaceae). Urushiol, an oil found mainly in the Anacardiads, causes an allergic skin rash on contact. Unlucky ones, like me, have worse reaction. But some people are even sensitive enough to get allergic reaction just from eating mango!

Just by brushing against the leaves. As bad as tick bite, if you can imagine.

Urushiol-induced contact dermatitis

The name Rengas actually refers to trees in the genera Gluta and Semecarpus. Here I refer the name to Gluta wallichii (I have been using this name to curse, and it really sounds like bad words). The Wallich's Rengas is actually quite common in our forest, especially at BTNR (70 big trees recorded in my survey), and they can grow quite big (the biggest Rengas I recorded is 78cm in diameter). However, we normally came across (and "kissed" by) saplings of our height. It is not difficult to spot them. Just look out for "black spots" (dried sap), just like those on mango skin.

Leaves of a Rengas sapling, ca. 30cm long (smaller and stiffer in big trees).

Some vegetative characters to identify Rengas.

Rengas' bark fissures like Seraya, but normally scattered with its infamous tell tale sign. Don't anyhow hug a "Seraya" if you are not sure what it is!

It's rare to find them fruiting, like most other rainforest trees. But if you see something like this in the future, it could be Rengas fruit. Picture here is the Rengas-like fruit of Swintonia schwenkii, a cousin of Rengas. See here for a dried Rengas fruit taken by lekowala at BTNR.

It's my laziness (of not wearing long) to be blamed for my rash, not Rengas. After all, at least we can spot a Rengas and avoid it, can't do that on ticks.

No matter what, I still love mango and cashew nuts.