You instantly become s a tree, growing in a split-second to the size of a fully-grown tree of  the same species used for the material component of the spell. The caster can add additional description of the tree, so long as that description is plausible for that tree (i.e. "many-limbed and easily climbed", or "a thin trunk with sparse limbs". The tree becomes deeply rooted into place on any solid surface and if impeded in its growth upward, it will break through stone or wooden materials no thicker than 2 feet, or metal no thicker than 1 inch. If it cannot break through, it will only grow to the height of the ceiling.

While in the form of a tree, the caster has -2 AC and cannot take any other actions other than ending their concentration. They are also vulnerable to slashing and fire damage, but are immune to effects that would cause them to be knocked prone or moved.

The tree, with consideration given to its description, can be climbed. Any creatures climbing this tree are considered to be in half-cover. However, whenever a creature not in the tree misses an attack with a spell or ability targeting a creature in the tree, the same attack roll applies to the tree as an accidental additional target.

If the spell ends while a creature is in the tree, there is the potential for fall damage if the creature cannot otherwise save itself. Similarly, the caster can break concentration where they are re-manifested at any location the tree’s trunk or limbs could reach, but will be in free-fall at that moment.