Rootar was created by Tom DeFalco and Paul Ryan in 1995 and first appeared in Fantastic Four # 398.
He has an arboreal physiology and limited control over various flora including his own body. The bark on his outermost surface provides him with heightened invulnerability. In addition to his membership in the Crimson Cadre he was born to Attilan parents, making him an Inhuman therefore he most likely received his powers from the Terrigen Mists.