Stele hypothesis was given by Van Tiegham and Doulet in 1886. According to hypothesis, the primary structure of root and stem is fundamently similiar which consist cortex as a major part and stele is located in the centre the two parts are separated by endodermis, which is the innermost layer of cortex, while stele is surrounded by pericycle. A stele consists of pericycle, vascular bundle and pith in it centre.