Physorg: Researchers at the University of Delaware have discovered a new reason why the tall, tasseled reed Phragmites australis is one of the most invasive plants in the United States. The UD research team found that Phragmites delivers a one-two chemical knock-out punch to snuff out its victims, and the poison becomes even more toxic in the presence of the sun’s ultraviolet rays. The study, which is published in the June issue of the scientific journal Plant Signaling & Behavior, is …