Cytological differentiation of the embryo sac in Boraginaceae

Abstract

In Lycopsis arvensis, Cerinthe minor, Lithospermum arvense and Echium vulgare the endosperm is divided into two parts: central and lateral. In Lithospermum and Echium, high podyploid single endosperm haustoria are formed and take part in nourishment of the embryo. In Lycopsis and Cerinthe, the lateral cells are lower ploid, while the polyploid synergids supply the embryo with nourishment.