Guwahati: A team of botanists has discovered and formally described a new plant species from Arunachal Pradesh’s Shi-Yomi district, showing the remarkable and still poorly explored botanical diversity of Northeast India.
The new species, Didymocarpus nautiyalii, belongs to the family Gesneriaceae and was discovered during a botanical survey conducted in April 2025. The species has now been formally described in the scientific journal Taiwania.
The research team is led by Madhusudhan Khanal of the G.B. Pant National Institute of Himalayan Environment, who conducted the field survey and discovered the plant in Shi-Yomi district.
The team also includes Devendra Kumar of the G.B. Pant National Institute of Himalayan Environment, Santosh Kumar Rai of Sikkim University, Dipankar Borah and Niku Das of the Department of Botany, Kaliabor College, Nagaon, and Momang Taram of Jawaharlal Nehru College, Pasighat.
What makes the discovery particularly striking is the plant’s apparent rarity. During the survey, the researchers located only 19 flowering individuals, occurring in two small subpopulations in Shi-Yomi district. Based on the currently known localities, its estimated area of occupancy is approximately 4 sq km.
The tiny herb grows on moist rock surfaces, particularly along roadside walls and near waterfalls, within subtropical evergreen forest at elevations above 1,000 metres. The species can easily be overlooked because of its small size and its tendency to grow among shrubs and in moist rock crevices.
The plant reaches only about 8 cm in height and bears distinctive bluish-purple flowers. Its short stem, leathery leaves and unusual funnel-shaped, slightly pouched flowers helped the researchers distinguish it from closely related species.
During the initial fieldwork, the plant was tentatively mistaken for a species of Henckelia. Detailed examination of its seasonal stems and cup-shaped calyx, followed by comparison with relevant scientific literature and herbarium specimens, revealed that the plant belonged to the genus Didymocarpus and represented a species previously unknown to science.
The researchers have named the species Didymocarpus nautiyalii in honour of Prof. Sunil Nautiyal, former Director of the G.B. Pant National Institute of Himalayan Environment, in recognition of his contributions to Himalayan environmental research and conservation.
The discovery also highlights the importance of continued botanical exploration in Northeast India. The region has historically experienced periods of limited botanical exploration and under-collection, leaving several remote areas poorly documented. Renewed botanical surveys in recent years have nevertheless resulted in the discovery of several new species and rediscoveries.
Although only two populations of D. nautiyalii are currently known, the researchers note that potentially suitable habitat occurs across a much wider area of Shi-Yomi district and surrounding landscapes. Further targeted surveys may therefore reveal additional populations.
For the time being, the researchers have assessed Didymocarpus nautiyalii as Data Deficient (DD) under the IUCN Red List criteria, because the currently available information is insufficient to determine its extinction risk.
The researchers recommend targeted surveys to locate additional populations, long-term population monitoring, and further studies on the species’ ecology, reproductive biology and habitat requirements.
The discovery adds another species to the growing botanical inventory of Arunachal Pradesh and underscores the importance of field-based taxonomic exploration in the Eastern Himalaya, where many plant species remain undocumented.