The structure and development of successive cambia and its products were studied in the stems of the halophyte Sesuvium verrucosum Raf. The young stem has several collateral vascular bundles arranged in a circle and separated by interfascicular zones. The secondary thickening begins with the differentiation of fascicular and interfascicular cambia which give rise to secondary xylem, phloem and lignified cells. | Annals of Agricultural Science 2015 60 2 203 208 H O S T E D BY Faculty of Agriculture Ain Shams University Annals of Agricultural Science locate aoas ORIGINAL ARTICLE Development of the successive cambia in Sesuvium verrucosum Raf Aizoaceae Ola H. Abd Elbar Agric. Botany Dept. Fac. Agric. Ain Shams Univ. 68 Hadayek Shoubra 11241 Cairo Egypt Received 29 June 2015 accepted 26 July 2015 Available online 11 November 2015 KEYWORDS Abstract The structure and development of successive cambia and its products were studied in the Sesuvium verrucosum stems of the halophyte Sesuvium verrucosum Raf. The young stem has several collateral vascular Successive cambia bundles arranged in a circle and separated by interfascicular zones. The secondary thickening begins Stem anatomy with the differentiation of fascicular and interfascicular cambia which give rise to secondary xylem phloem and lignified cells. This normal cambium ceases to divide after a limited period of activity. A new segment of anomalous cambium was developed from the phloem parenchyma cells outside the normal previous cambium. These cells are served as a site for the origin of the anomalous cambium and subjected to repeated periclinal divisions. This cambium has fusiform cells with semi-storied appearance. The activity of this anomalous cambium produces secondary xylem phloem fibers and soft parenchyma as conjunctive tissues. The formation of subsequent cambia followed a similar pattern of development and causes vascular increments in the old stem. So the old stem of S. ver- rucosum is constructed of concentric fibrovascular bands separated from each other by cylinders of conjunctive parenchyma tissue. This internal structure has a great adaptive potential to the halo- phyte S. verrucosum. This can be detected by the following points 1 Production of large number of vessels and sieve tubes elements increases the conductive activity 2 Occurrence of fibers along- side the vessels increases the .
