Plant door

Plant door was an alteration spell that created a passageway through thick vegetation, allowing easy passage or concealment.

Effects
This spell opened a magical corridor wide by  tall whose length could be up to  per level of the caster. The passage had to have sufficient vegetation (trees, thickets, undergrowth, etc.) either natural or magically created (by the overgrowth version of plant growth for example) and the entrance was only visible to the caster, druids of equal or higher level, or dryads.

Plant door could also be used to "step inside" a tree for concealment of medium sized or smaller creatures, subject to space limitations. If a tree being used as a hiding place were burned or cut down, those within had to exit before the tree was consumed or severed, or else perish with the tree.

This spell lasted for tens of minutes depending on the experience of the caster. If used to hide in an ash tree, the duration was three times longer; an oak tree extended the duration by a factor of nine. This spell had no effect on plant-based lifeforms such as treants, shambling mounds, molds, slimes, etc.

Components
In addition to verbal and somatic components, this spell required a small lump of charcoal or the druid's usual mistletoe.