Revisiting Nawaschin: Does Double Fertilization not Occur in the Family Orchidaceae?

Double fertilization is widely regarded as a general feature of all flowering plants. However, Sergei Nawaschin, the finder of double fertilization phenomenon, held the opinion that it did not occur in Orchidaceae. According to his description, fusion between the polar nuclei and the second sperm cell did not occur in Orchidaceae, which he claimed was a general characteristic of the family. In recent years, more and more evidence of the second fertilization in Orchidaceae has been accumulating, indicating that double fertilization occurs ‘as is normal’ in this family.