Orchids, gorgeous and elegant, are also some of the most deceitful flowers, having evolved sometimes elaborate ruses to lure pollinators.

In a new study of the most brazen of these botanical cheats, the species that entice pollinators with false promises of sex, scientists have discovered that one group of orchids has taken the art of manipulation to shameless heights.

Sexually deceptive orchids, as biologists have long known, look and can even smell so much like a female insect that males will try to mate with the flower in a sometimes vigorous process that can result in pollination. But scientists now report that the tongue orchids of Australia are such thoroughly convincing mimics of female wasps that males not only try to mate with them, but they actually do mate with them  to the point of ejaculation.

“It’s always been described as pseudocopulation,” said Anne Gaskett, a graduate student at Macquarie University in Australia and the lead author of the study. “But it looked like true copulation to me.”