2019: Course Director for the Third Botanical Nomenclature Course organized by the Botanical Survey of India and ENVIS Centre on Floral Diversity-BSI in Coimbatore
2019: Memento: For being the Course Director for the Third Botanical Nomenclature Course, Coimbatore (March 2019)
2018: Course Director for the Botanical Nomenclature Course organized by Prof. Maria do Carmo E. Amaral, Depto. de Biologia Vegetal, IB-UNICAMP, Brazil
2017: Course Director for the Second Botanical Nomenclature Course organized by the Botanical Survey of India and ENVIS Centre on Floral Diversity-BSI in Pune
2017: Memento: For being the Course Director for the First Botanical Nomenclature Course, Kolkata (January 2013) and the Second Botanical Nomenclature Course, Pune (February 2017)
2016: Honorary Membership in Indian Association for Angiosperm Taxonomy
2013: Course Director for the First Botanical Nomenclature Course organized by the Botanical Survey of India and ENVIS Centre on Floral Diversity-BSI in Kolkata
2012: Green Carpet Award: as a member of Organismic & Evolutionary Biology Department Green Team, Harvard University
2011: Honorary Membership in East Himalayan Society for Spermatophyte Taxonomy (EHSST)
2010: Distinguished Service Award: given by the American Society of Plant Taxonomists at the banquet on 3rd August 2010, during the annual Botanical Society of America conference held in Providence, Rhode Island, 31 July--4 August 2010
1998: Honorary Membership in New England Botanical Club (NEBC)
1994: The Donovan Stewart Correll Memorial Award: given for the year 1994 by the Native Plant Society of Texas for excellence in scientific writing in the field of native flora of Texas. The book "Checklist of the Vascular Plants of Texas" (published in 1990) was chosen for this award.