A tarry vine attacking Tem Barkwater.

Tarry vines were plants universally feared by the inhabitants of the Deepwoods. These sinister vines formed symbiotic relationships with the giant, flesh-eating bloodoak trees, which they helped to ensnare prey. They then fed on the victim's blood while their host gorged on the flesh. If a vine was ever severed, three new vines grew in its place. This could be prevented by cauterizing the stump with a flame.

Even Deepwoods creatures were afraid of tarry vines and instinctively avoided areas where one was know to grow, resulting in large, empty clearings in the near vicinity of bloodoaks.
Any creature that strayed into one of these clearings was almost certain to be trapped by the tarry vine. The atmosphere in these clearings was know to Deepwoods tree-fellers as "deathstillness".

When harvesting bloodoak timber, it was common practice to use slaves to distract the tarry vine while the rest of the party attacked the blookoak. Since these slaves were generally considered disposable bait, many lost their lives simply so that the rich, powerful upper class could use prime timber.