From publisher blurb:
Avalon takes a common spell and provides you with a number of alterations and additions to add excitement and useful options for your next adventure. Each issue of Avalon Spell Books will focus on a new spell, discussing different versions of the spell, providing different components that can be used to alter the way the spell works, and even adding feats and new magical items linked to the spell in question.
Tree Shape. Most spellcasters do not even remember this spell exists except under some extraordinary circumstances. Lacking any natural inclination towards serene photosynthesis, they use it when they need to stay motionless and unnoticed somewhere dangerous for many hours, or when their companions need a “large, dead, tree trunk” to get across a particularly nasty stream.
Or maybe when the group wants some shade in the middle of a desert.
Rooting and vegetating still offer more interesting experiences for patient spellcasters, ready to look for new magics in arboreal life. The first option of interest is the fact that a tree can sleep wherever it can root, ignoring many inconveniences that would give a humanoid a bad night. It is fully possible to sleep while being a tree, even getting a proper night’s rest, provided the shapechange duration is long enough. Much like a normal sleeping character, the dormant tree has reduced Perception abilities. If the spell duration ends before the character gets enough rest, the event should be treated as any other hazardous awakening in the game.
Then there is using Tree Shape underwater. Yes, contrary to popular belief, one can do so—in this case the spell transforms the caster into a large kelp, firmly attached to the river- or seabed, instead of a common shrub. In case of any doubts, the Game Master may require the character to succeed at a Knowledge (nature) check DC 15 to choose a proper plant type in which to transform. Since kelp can “breathe” water perfectly, the caster does not need any additional means of water-breathing for as long as the spell duration lasts.
This and much more is discussed in this issue of Spell Books!