Oleanane is the name given to a chemical produced by many flowering plants, which has a suppressing effect on some insect threats. Classes Magnoliopsida- Dicots Liliopsida- Monocots The flowering plants (also called angiosperms) are a major group of land plants. ...

It is considered a key marker differentiating flowering plants from other life, and in fact has been used in the effort to determine the evolution of flowers, called the Abominable Mystery by Charles Darwin because it had been so poorly explained by the fossil record, which has only recently begun to change. Clivia miniata bears bright orange flowers. ... In his lifetime, Charles Darwin gained international fame as an influential scientist examining controversial topics. ...

This chemical appears, in fact, to have been shared by a group of plants called gigantopterids, which lived twice as long ago as the oldest known flower fossils, yet are now thought to probably have been close relatives, moving the appearance of flowers from 130 million years to a possible 250 million years ago. Gigantopterid is the name given to fossils of a group of plants existing 250 million years ago, which bore many of the traits of flowering plants, quite possibly having been a close relative, but are not proven to have flowered, themselves. ...