Brambleweed has finger-length thorns, sharp and sturdy enough to rend flesh. The plant’s thick vines spread across an area, hindering any who enter it.

    Effect: Brambleweed squares are difficult terrain. A creature that starts its turn in a brambleweed square takes 5 damage per tier. A creature that ends its turn in a brambleweed square is restrained until the start of its next turn.
    Usage: Brambleweed can survive in areas of defiled ground, taking its nutrients from passing creatures rather than the surrounding soil. As a result, defilers use the plant to ward their territory. In the wilds of Athas, shrewd predators and hunters weaken prey by herding it into patches of brambleweed.

Published in Dark Sun Creature Catalog, page(s) 134.