The present research project is focused on the species-rich, taxonomically complex genera ie. Amaranthus and Alternanthera (Amaranthaceae), with systematic considerations pertaining to infraspecific and intergeneric relationships. Monophyly of a genus is important for a stable classification system, which is being tested here explicitly. Topology of recent phylogenetic studies received no statistical support and requires further investigations. Thus, the present study focuses on investigating the generic status, monophyly versus non-monophyly, using molecular phylogenetic approaches.