In which of following plants were mutations discovered by Hugo De Vries ?

Mutations were discovered by Hugo De Vries in Oenothera lamarckiana. This plant is commonly known as Evening Primrose. He formulated observations by experimenting on this plant. He took a normal plant and self pollinated it to raise seeds. He found that when these seeds grown into plants, all the plants were normal and they were showing only minor variations. A few were different from the parents in many characters. In further generations, these different plant gave rise to few more different plants than their parents. De Vries named these minor variations as 'mutations'. He found that mutations were sudden and they were inherited from the previous generations.