Mandayam Osuri Parthasarathy Iyengar obtained his PhD (1932) from the University of London, UK. His specialization was in botany and algology. He was a Professor of Botany, Presidency College, Chennai and of University Botanical Laboratory, University of Madras.

Academic and Research Achievements: Iyengar contributed a great deal to the science of algae such as systematics, ecology, phytoplankton studies, algal associations, geographical distribution, cytology, and handling of type specimens. His contribution to the origin and evolution of plant life by the erection of the genus Fritschiella is noteworthy. He did extensive work on algal floras of temporary waters and their succession, algal blooms, paddy-field algae of estuarine regions, and algae in relation to aquatic animals.

Other Contributions: Iyengar established a flourishing school of algology in the University of Madras. He served as Editor of Journal of Indian Botanical Society.

Awards and Honours: Professor Iyengar was a recipient of Birbal Sahni Medal of Indian Botanical Society and Sunder Lal Hora Medal of INSA (1960). He was a Fellow of Linnaean Society of London, American Association for the Advancement of Science, Indian Academy of Sciences, Bangalore, Indian Botanical Society, International Phycological Society (President), and Phycological Society of India (President). He was President, Botany Section of Indian Science Congress (1927) and Honorary President of International Botanical Congress (1954).