Mellissa Reeves plays Rhizobium Meliloti when she's the cute, adorable, spunky side-kick of Robert Kanigher's .. Poison ivy.... Alethia Wagner and embeth Davidts.. two actresses who look exactly alike.. they both share the role of the adult, thirty-year old Rhizobium Meliloti when she's grown to become a mature, cerebral, sophisticated, aristocratic, fiercely introspective, full-blooded woman....