Justification
This species is endemic to northeast India and reported to be found only in Nokrek Biosphere Reserve in the Garo hills of Meghalaya, Dailong forest of Manipur and Behali forest of Assam. There are nine known localities for this species. The species is unevenly distributed, with instances of small subpopulations containing isolated individuals, contrasting with larger subpopulations characterized by a high number of individuals spanning a range of a few kilometres (Malik et al. 2006). The total number of mature individuals is estimated at approximately 800–900 (S.K. Malik pers. comm 2024). The threats include, large scale deforestation for jhum cultivation, extensive firewood collection, human habitat extension, remarkably low genetic diversity, specific habitat requirements, and limited regeneration. All these factors pose significant risks to the sustainability of natural populations. It is not reported from any ex situ collection. The species is assessed as Vulnerable.
Geographic Range Information
The species is endemic to northeast India and reported to be found only in Nokrek Biosphere Reserve in the Garo hills of Meghalaya, Behali Reserve Forest of Assam and Dailong forest of Manipur (Malik et al. 2006, Borah et al. 2018, Devi et al. 2022). The species was also listed to be found in Naga hills of Nagaland and Kaziranga reserve forest in Assam but further surveys confirmed these as erroneous (Singh and Singh 2003). The species is unevenly distributed, with instances of small subpopulations containing isolated individuals, contrasting with larger subpopulations characterized by a high number of individuals spanning a range of a few kilometres (Malik et al. 2006).
Population Information
There are nine known collecting sites for this species. Five are in Meghalaya (in the buffer zone of Nokrek Biosphere Reserve in the east, west and south Garo hills of Tura, Willaims Nagar and Bakhmara district), three in Manipur (forest area of Diaong village) and one in Assam (Behali Reserve Forest) (Malik et al. 2006, Devi et al. 2022, Borah et al. 2018). In Behali Reserve Forest seven plants were recorded, of which three had only flowers, two with fruits and flower-buds, one sapling and one old plant with coppices; 42 individuals were found in Dailong forest area. The total number of mature individuals is estimated at approximately 800–900 (S.K. Malik pers. comm 2024).
Habitat and Ecology Information
Citrus indica plants in the wild vary from thorny bushes to climbers of 3–4 m in height. Flowering period remains active from early September to January and fruiting is observed during mid-October to February. The species appears to be localized to areas with a microclimate of tropical and mild temperate seasons and very high humidity and rainfall (Malik et al. 2006). The species grows in association with Zanthoxylum armatum, Melocanna baccifera, Castanopsis hystrix [C. purpura subsp. purpurea per POWO (2023)], Mesua ferrea, Albizia lebbeck, Tectona grandis, Quercus griffithii, Dendrobium chrysanthum, Vanda coerulea and some wild edible mushrooms (Devi et al. 2022).
Threats Information
The species habitat has been facing high pressure due to large scale deforestation, illegal logging, jhum cultivation, extensive firewood collection, extension of human habitation, and dependence on forest products (Singh 1981, Malik et al. 2006, Borah et al. 2018, Devi et al. 2022). The species faces low genetic diversity, high habitat specificity and low regeneration, all these factors pose serious threats to its natural population (Kumar 2010).
Use and Trade Information
This fruit has gained recognition in the Garo hills of Meghalaya and is frequently utilized by the local population, particularly those belonging to the Garo tribe, including for medicinal purposes in treating chronic diseases. Both whole raw fresh fruits and dried fruit powder are administered as a remedy for severe communicable diseases such as smallpox. Moreover, the fruit is ingested to address jaundice and other related stomach ailments in both humans and domestic animals. Beyond its medicinal uses, the fruit holds significant value in the religious rituals of the Garo people, particularly during their final rites. There is a tradition where a fresh fruit from this species is positioned on the deceased body before carrying out the final rites. This practice is rooted in the belief that it helps ward off spirits from other family members (Malik et al. 2006)
Conservation Actions Information
The species is located within the Behali Reserve forest, Assam and Nokrek Biosphere Reserve in the Garo Hills of Meghalaya. Conservation efforts began a century ago with the establishment of the Citrus Gene Sanctuary in the Nokrek Biosphere Reserve. Despite attempts at propagation from seeds, the species encounters challenges in growth and survival outside its natural habitat. The National Bureau of Plant Genetic Resources (NBPGR) in Delhi has safeguarded the pollen and seeds in the cryo-gene bank dedicated to this species (Malik et al. 2006). However, more ex situ and in situ conservation efforts are needed. The species is not reported from an ex situ collection (BGCI 2023).