By casting this spell upon a plant with leaves, the caster can hear anything that happens within 50 feet of another plant of the same type, which must be within 50 yards of the target plant per caster level. The caster must be aware of the location of the other end of the leaf ear and cannot simply listen "to hear what is out there." Therefore, it must be in an area he has been before. In all other regards, it is as if the priest were present. Note that the priest can't be affected by sound-based attacks through the leaf ear.
The material components of this spell are two plants of the same type within 50 yards, neither of which is consumed in the casting.