Parchwood is a block of Wood taken from a Parchwood-tree with golden-brown cloud-like tree-tops.
Parchwood-trees can set on fire unintentionally easily, as the Savannah is a hot biome. If you place a torch under a block of Parchwood, Parchwood Leaves or any flammable material close to a tree, the whole tree can catch fire quickly and burn down, additionally to more trees and/or every flammable block close by. This fire cannot be extinguished currently, only stopped by pulling enough blocks away for an aisle so the fire cannot leap across to consume more blocks.
Parchwood-trees cannot be grown from Saplings (yet).
Parchwood can be corrupted, like by Corrupt Bombs or Corrupted Water for example, or placing Corrupted Wood on/next to blocks of Parchwood touching them. Corrupted Wood makes Fuel of much higher quality, but has to be picked up by using Lumite Mining Cells.
Unprocessed Parchwood can be used to craft a number of starting recipes in the Crafting Menu or at a Crafting Table in older worlds created before September 2015), like Wood Mining Cells, Processors or Moss Torches.