Abstract:The structure of roots, stems and leaves in Siraitia grosvenorii is roughly similar to that in other plants of Cucurbitaceae. Differences in three repects are observed: ( a ) There are five vascular bundles in the midribs of the leaves, ( b ) There exist groups of silica cells in leaves, ( c ) The root tubers show anomalous secondary growth. In secondary xylem, a series of supernumerary cambia form around the tracheary elements. Many small vascular bundles with xylem and phloem differentiate from the supernumerary cambia.