Poisonous plants off-road: what are they?

[Constantine Phaulkon]

In the temperate east coast USA there is the "Poison Ivy" plant (Toxicodendron radicans), very numerous off-road, which will give most people a bad rash. In the tropics, what? The only thing I can think of: poisonous plants in the Alocasia family ( http://en.wikipedia.org/wiki/Alocasia ). Of course if you have the good habit of not touching anything when off-roading I suppose you'll never know (and what you don't know won't itch you).

 

[alexuk]

theres one thing that's given me an itch like a bee sting/rash a few times, it must be a plant I've brushed against whilst riding. But I have no idea what it is.
There is a bean that grows on a vine, it's pods look hairy and brown. The hairs are used in itching powder, be very careful with these, it's called "mad bean" in some places, cos when you scratch your fingers transfer the itch to other parts of your body, so you scratch all over

 

[Constantine Phaulkon]

Thanks alexuk. Also nettles. I forgot about nettles. Do they have nettles in Thailand? I guess so ("Nettles constitute between 24 and 39 species of flowering plants of the genus Urtica in the family Urticaceae, with a cosmopolitan though mainly temperate distribution. ... Milarepa, the great Tibetan ascetic and saint, was reputed to have survived his decades of solitary meditation by subsisting on nothing but nettles; his hair and skin turned green and he lived to the age of 83. "-- Wikipedia)