What was the accidental discovery that Hugo DeVries made?

In his own time, De Vries was best known for his mutation theory. In 1886, he had discovered new forms among a display of the evening primrose (Oenothera lamarckiana) growing wild in an abandoned potato field near Hilversum, having escaped a nearby garden.

Explanation:

The new forms of mjtations?

He discovered new forms among a display of the evening primrose (Oentheralamarckiana) growing in an abandoned potato field near Hilversur