Petunia (image) Institute of Science and Technology Austria Share Print E-Mail Caption The stigma of Petunia contains a toxin that stops pollen growth. Pollen in turn has a team of genes that produce antidotes to all toxins except for the toxin produced by the "self" stigma. Credit Lewis Collard Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.