these plant-objects cannot be grown through the crafting system.. they must be module-placed in select areas.
PC's with "Ranger(2)" or "Druid (3)" or "Bard(4)" may do a -investigate command with the plant... and get a whisper return of any PC creatures that have passed through, similar to questioning NPC's
-this is based on the 3rd edition spell. "Speak with Plants"
http://forgottenrealms.wikia.com/wiki/Speak_with_plantsSpeak with plants was a divination or alteration spell that allowed the caster to converse in very simple terms with vegetative and fungoid life forms.
-underdark plant could be a mushroom... surface plant could be a non-shrub.
If the placable is destroyed by a player, it respawns at the next server reset. -this is so PC's who wish to mask their passing can prevent snooping ranger-scouts from learning if they passed or not.
-Maybe add this quality to placeable TREES that... if 'cut-down' the tree looses it's record of PC's that passed it, and when it spawns again, the records reset themselves.