| 100 Red listed medicinal plants of conservation concern in Southern India K Ravikumar, DK Ved, R Vijaya Sankar, PS Udayan | 335 | 2000 |
| Some common plants used by Kurichiar tribes of Tirunelli forest, Wayanad district, Kerala in medicine and other traditional uses PS Udayan, MK Harinarayanan, KV Tushar, I Balachandran CSIR, 2008 | 54* | 2008 |
| Medicinal plants of Arya Vaidya Sala, Herb Garden PS Udayan, I Balachandran Centre for Medicinal Plants Research (CMPR)-Vaidyaratnam PS Varier's Arya …, 2011 | 41 | 2011 |
| Ethnomedicine of the Chellipale community of Namakkal district, Tamil Nadu PS Udayan, S George, T KV, I Balachandran CSIR, 2005 | 39 | 2005 |
| Medicinal plants used by the Kaadar tribes of Sholayar forest Thrissur district, Kerala PS Udayan, S George, KV Tushar, I Balachandran NISCAIR-CSIR, India, 2005 | 37 | 2005 |
| Medicinal plants used by the Malayali tribe of Servarayan Hills Yercad Salem District Tamil Nadu India PS Udayan, S George, KV Tushar, I Balachandran Zoo's Print J 21 (4), 2223-2224, 2006 | 35 | 2006 |
| Ethnomedicinal information from Kattunayakas tribes of Mudumalai wildlife sanctuary, Nilgiris district, Tamil Nadu PS Udayan, KV Tushar, S George, I Balachandran CSIR, 2007 | 34 | 2007 |
| Floristic diversities and medicinal importance of selected sacred groves in Thrissur district, Kerala MR Deepa, P Sheema Dharmapal, PS Udayan Tropical plant research 3 (1), 230-242, 2016 | 19 | 2016 |
| Chemical composition and antimicrobial activity of the essential oil from bark of Pittosporum dasycaulon Miq CT Sadashiva, P Sharanappa, AB Remashree, AV Raghu, PS Udayan, ... Advances in biological research 4 (6), 301-304, 2010 | 17 | 2010 |
| Syzygium sasidharanii sp. nov.(Myrtaceae)–A new species with edible fruits from Agasthyamala Hills of Western Ghats, India P Sujanapal, AJ Robi, PS Udayan, KJ Dantus International Journal of Advanced Research 1 (5), 44-48, 2013 | 16 | 2013 |
| A new species of Salacia (Hippocrateaceae) from south India PS Udayan, R Yohannan, MS Devipriya, V Devipriya, AK Pradeep Edinburgh Journal of Botany 69 (2), 255-258, 2012 | 15 | 2012 |
| Taxonomical and phytosociological studies on Chithalikavu-A sacred grove, Thrissur district, Kerala MR Deepa, PS Udayan, KA Anilkumar Tropical Plant Research 4 (1), 20-30, 2017 | 14 | 2017 |
| Gentiana kurumbae, a new species of Gentianaceae from the Western Ghats of Kerala, India KA Anilkumar, KMP Kumar, PS Udayan Taiwania 60 (2), 81-85, 2015 | 13 | 2015 |
| A taxonomic revision of the family Lauraceae from South India AJ Robi Kannur, 2014 | 13 | 2014 |
| Salacia vellaniana Udayan, Yohannan & Pradeep (Celastraceae), a new species from India PS Udayan, R Yohannan, MS Devipriya, V Devipriya, AK Pradeep Candollea 68 (1), 147-149, 2013 | 13 | 2013 |
| Some common medicinal plants used by the Nayaka community, Savandurga forest of Magadi taluk, Bangalore rural district, Karnataka, India PS Udayan, S George, KV Tushar, I Balachandran Journal of Natural Remedies, 35-40, 2005 | 12 | 2005 |
| Ethnomedicine of Malapandaram tribes of Achenkovil forest of Kollam district, Kerala U PS, S George, KV Tushar, I Balachandran CSIR, 2007 | 11 | 2007 |
| Tinospora sinensis (Lour.) Merr. from Sickupara, Kolli Hills Forest, Namakkal District, Tamil Nadu PS Udayan, S George, KV Tushar, I Balachandran Zoos’ Print Journal 19, 1622-1623, 2004 | 11 | 2004 |
| Medicinal plant species of Andhra Pradesh community forestry project area DK Ved, PS Udayan, K Ravikumar, N Begum, R Karthikeyan Foundation for Revitalisation of Local Health Traditions, Bangalore, 46, 2002 | 11 | 2002 |
| A new species of Tinospora (Menispermaceae) from South India PS Udayan, AK Pradeep, I Balachandran Edinburgh Journal of Botany 66 (1), 77-80, 2009 | 10 | 2009 |
