The evergreen tree Buchanania barberi Gamble of the family Anacardiaceae is endemic to the South Western Ghats of Kerala, India. The first herbarium specimen of the species was collected in Nadarai, Thiruvananthapuram, in 1904 by C.A. Barber and the species was described by J.S. Gamble in 1916 (J.S. Gamble, 1916, Notes of the Flora of Madras. Kew Bulletin, 135). The species was categorized as Endangered in the Red Data Book of Indian Plants in 1990 and as Critically Endangered on the IUCN Red list in 1998. The species was rediscovered by staff of the Jawaharlal Nehru Tropical Botanic Garden and Research Institute (JNTBGRI) in the Palode region of Thiruvananthapuram in 2001 (Santhosh Kumar et al., 2002, Rheedea, 12, 197–200). In 2005 the species was included in the national priority list of endangered plants.
In 2016 Botanic Gardens Conservation International, UK, made a grant to JNTBGRI to support research on this species. A total of 11 field surveys were carried out in the Palode region (c. 74 m altitude) from July 2016 to June 2017. Four individuals were recorded, of which two were adult and two were juvenile trees. The area of occupancy of the species is <5 km2. This species has no clonal growth and propagates by seeds. Our surveys and information obtained from interviews with local people reveal: (1) low fruit production despite high levels of flowering (2) no record of establishment of seedlings, (3) consumption of the fruits by birds, (4) low seed germination as a result of dormancy and unfavourable conditions, and (5) the impact of development programmes in the area, especially road expansion.
Our research on seed collected in April 2017 indicates delayed germination with dormancy. Experimentation with methods to break dormancy and establish seedlings are being carried out. Further research and surveys are required in South Kerala, with the help of local forest range officers and taxonomists, to elucidate fully the conservation status of this rare and Critically Endangered species.
We acknowledge support from Botanic Gardens Conservation International, UK (grant no. A217).