Take a trip to SE QLD and pic any walk FC
. The moment you find a nice moist gully it will be sat there on the edge of the rainforest.
As for treatment its more an attempt to get the fine hair like stings back out. Most carry gaffa tape for this purpose or wax strips (though be wary in the summer months as they'll melt all over your gear). I know one poor bloke who sat on a leaf (yes even when dead and rotting on the ground they'll still get you) and had forgotten his tape. Even after 18 months the area still burns with incredible pain if in contact with water etc and is only now calming down. Nasty stuff.