Desmid Tree

Desmid trees are gnarled, leafless trees with ochre bark capable of producing the desmus, a caustic miasma of gas which protects the tree from herbivores.
The tree is prized by wizards for its heartwood, which can be used to make an exceptional Wand of Vitriol.

Desmus Gas

This unusual defense mechanism is slow-acting, but lethally caustic. The desmus melts most materials--from wood to metals to flesh; glassteel, copper or black dragonscale, and the desmid wood itself is are among the very few acid-resistant materials not damaged by the miasma.
Desmus is temporarily dispersed by any moderate wind, but the desmid tree quickly produces larger quantities in response. Strong, persistent winds are required to overpower the tree's defenses and keep the desmus' presence at a safe level.

Habitat

Desmid trees grow among the inhospitable, craggy deserts of West Bharazad. Their desmus gas wards away most intelligent beasts, and melts the rest into heaps of liquid flesh, bone and chitin. When this molten flesh accumulates, it often seeps into the earth and emerges later as a sentient ooze. Particularly old desmid trees, or a desmid orchard, are often slicked with caustic ooze and part-corroded victims.

Desmid trees as defence

The copper and black dragonflights of Western Bharazad are known to hold a particular fondness for the desmid tree. Their natural resistance to acid makes the trees a natural defensive mechanism for their lairs, capable of deterring would-be looters from a dragon's hoard when the dragon or their followers are absent.

Desmid trees as punishment

Among the yuan-ti of West Bharazad, the desmid trees are a source of unconventional (and controversial) punishment reserved for the most heinous crimes among yuan-ti society. A figure unfortunate enough to be sentenced to 'death by corrosion' is fixed to a desmid tree--using the tree's own branches as lashing--and left upon the tree until melted.