adjisobilateralhaving identical parts on each side of an axis
Century Dictionary and Cyclopedia
isobilateralIn botany, having the flanks of the organ flattened surfaces: applied to a particular kind of bilaterally symmetrical organs, as the leaves of some species of Iris, in contradistinction from bifacial or dorsiventral organs, or those with an evident upper and under surface, as in most leaves.
Chambers's Twentieth Century Dictionary
adjIsobilateralī-so-bī-lat′e-ral (bot.) having the flanks of the organ flattened surfaces.