- Category : 1852-births
- Type : GP
- Profile : 4/6 - Opportunistic / Role Model
- Definition : Split - Large
- Incarnation Cross : RAX Maya 1
French pharmacist and botanist credited along with Russian biologist Sergei Navashin as the co-discoverer of double fertilization in flowering plants. The two men made their discoveries independent of each other, Navashin in 1898 and Guignard in 1899. He also introduced a new method for detecting the presence of hydrocyanic acid in plants. In addition, he conducted significant research on the origin and structure of integuments for a large number of seeds. He died on 7 March 1928 in Paris, aged 75.