Poisonous Princesses Versus Roses and Thorns

Rose and Thorn, two women with two conflicted alter egos, making them four times the threat. On on world, the Thorn persona was a force for good, on the other, she was an agent of evil. On both worlds, Rose was an innocent bystander overwhelmed by her more dominant dormant personalities, which came out when injustice lurked. The catalyst for the Earth-One Thorn was avenging her police detective father's death at the hands of the Metropolis crime gang known as the 100. The catalyst for the Earth-Two Thorn was to feed her insatiable greed, forming a gang operating in Keystone City.

Each Thorn had a various adversaries, and met costumed crusaders such as Superman and the Flash who were either a friend of a foe. Two lethal ladies proved particularly dangerous when facing Thorn and Rose. These lasses were Pamela Isley aka Poison Ivy and Princess Maru aka Doctor Poison.

Poison Ivy was recruited by the 100's leader Vince Adam, using an alien computer known as K.A.R.L., into implement a scheme to capture his arch-foe the Thorn. Then computer suggests that Ivy seduce a sculpture named Malyun into inviting the Thorn to be use her body as a mold for his latest sculpture, for which he will donate a sizable amount to a local charity. Agreeing to do this, Thorn is tricked into becoming immobilized, and then her body is dumped into a nearby river. The computer begins feeling remorse, and when it too is dumped next to the Thorn, it radiates heat the melts her gold encasing. Freed, Thorn swimmed to the surface to find Poison Ivy and decisively defeats Ivy.

Doctor Poison was held captive, along with several other supervillianess, on the Amazon's Reformation Island. Freed of a training girdle by the criminal mastermind of Saturn known as Eviless, Princess Maru joins her new Villany, Inc. as Maru once more wears her Doctor Poison disguise. After initially capturing her arch-enemy, Wonder Woman, the Doctor and her fellow allies Cheetah, Blue Snowman and Eviless are overpowered by the heroine will rowing away from their prison. Quickly, the quartet once more subdues Wonder Woman, and return to the island. Once there, fellow female prisoners who have reformed... which at this point would've included the evil Thorn's alter ego of Rose... helped to recapture Maru and all except four remaining female felons.

While Poison Ivy used this occasion to reintroduce herself into the criminal community some time after her two capers which Batman and Robin thwarted, this was the last time Princess Maru appeared as Doctor Poison. 

Maru apparently grew content living among the Amazonian from then on, although around this same time another femme fatale would take her place in tormenting Wonder Woman, when the Huntress fought the heroine and her Justice Society allies. This golden age Huntress had seven separate battles versus her arch-enemy Wildcat, which mirrored seven separate encounters between Poison Ivy had with Batman.

Meanwhile, the Huntress of Earth-One followed the example of Doctor Poison of Earth-Two, reforming of her evil ways after just three appearances, unlike the Earth-One Poison Ivy, who joined the Injustice Gang just as the Earth-Two Huntress joined the Injustice Society (and Secret Society of Super-Villians).