Embryogeny

Embryo in orchids is a mass of undifferentiated cells. But in the ontogeny of this mass of cells, there are differences which are consistent with the concepts of relatively primitive and advanced status of the corresponding species. The two major types of embryos in orchids are the suspensorless and the suspensored. The suspensorless embryo is considered primitive and is found in Cypripedium and in genera like Spiranthes, Listera, Neottia etc. of ttribe Neottieae. Among embryos with suspensors, Swamy ( 1949 ) recognises 5 types - the single celled suspensor of Paphiopedilum, Epipactis, Goodyera and Vanilla. The second type of the haustorial type is confined to the Orchideae. The other types are found in Epidendreae.