Abstract: The present paper deals with the embryological studies of the Gastrodia clata The eyt.okinesis of microspores is of the simultaneous type during the tetrad formarion. The compound pollen grains stick together to form the massulae. The massulae are of different size and they consist of several hundreds to about one thausand pollen grains. There are 300 400 massulae contained in an anther. The tapetal layer is of secretory type and its cells are uninue]eate. The structure of the ovule is much reduced, with single integument and no formation of the micropyle. The megaspore is covered in one layer nueellar epidermis, there is only a single nueellar cell at ehaiazal end in section. The nmture embryo sac consists of four ceils and belongs to the reduced form of the Polygonum type. The interval between the pollination and the fertilization is about four days and the double fertilization proceeds normally. The primary endosperm cell divides rarely and degenerates completely 6–7 days after fertilization. The zygote begins to divide one to two days after fertilization. It takes 20–21 days from the pollination to the maturation of the seed. The artificial germination rate of seeds reaches above 85% after 16–20 days.

Key words: Gustrodia clata Blume (Orehidaceae), embryology