EN
The data concerning endosperm type in Chondrilla juncea L. from Europe, Asia and Australia have been the subject of controversy. This study investigated the problem embryologically in an individual plant growing on an experimental field. Two endosperm types, nuclear and cellular, were observed to be present in inflorescences of the same plant. Both types of endosperm were formed after open pollination as well as after emasculation; however, cellular endosperm predominated slightly after open pollination. The development of endosperm preceded embryo development independently of endosperm type. Intraspecific variability of endosperm type in the investigated plant seems to be genetically conditioned, and it may be modified by external conditions.