Some features of showy sundrop (Oenothera speciosa Nutt.)

Abstract

The paper presents the results of studying the processes of formation of male and female generative structures, as well as fertilization in a representative of the Onagraceae family - evening primrose ( Oenothera speciosa Nutt.), which naturally grows in Europe, in the southern regions of the United States and in Mexico. Under the conditions of introduction on the Southern Coast of the Crimea, the main reproductive processes are within the normal range and can form viable sexual elements that ensure an effective fertilization process and the development of valuable seeds. It has been established that the wall of the microsporangium develops centrifugally; mature pollen grains are usually 2-celled. The ovule is anatropic, bitegmal, crassinucellate, the embryo sac is monosporic of the Oenothera-type, but there are also embryo sacs of the Polygonum-type.