Distribution and diversity of Garcinia L. in Upper Brahmaputra Valley, Assam

The genus Garcinia (family Cluciaceae) with its 400 species is reported to distribute in tropical parts of the world. The genus has 36 species in India mostly in forest as well as in non-forest areas of North-East, Western Ghats, and Andaman and Nicobar Islands. Of which, 16 species are endemic in India. Garcinia in Assam is locally known as Thekara and use for timber, food and medicinal values. However, the genus found to be disappearing from natural habitat in Assam. This study was conducted to survey in different forests, patch vegetations and homesteads on distribution, diversity and status of Garcinia species in Upper Brahmaputra Valley of Assam. The study recorded 10 species of Garcinia i.e. Garcinia pedunculata Roxb., G. paniculata Roxb, G. cowa Roxb. G. morella Desr G. kydia Roxb., G. xanthochymus Hook., G. dulcis (Roxb) Kurz., G. spicata (Wight & Arn) Hookf., G. lanceifolia Roxb. and G. sopsopia (Buch.-Ham.) Mabb. The study also revealed that except G. lanceifolia all these species were available in different evergreen and semi-evergreen forests with specific plant communities like Holong-Morsal-Nahor, Holong-Mekai-Nahor association. Moreover, G. pedunculata, G. xanthochymus, G. cowa and G kydia were recorded from the patch vegetations around the villages. Garcinia lanceifolia, which is a small tree of the genus, was found only in the homesteads. Out of 12 reserve forests (RF) of Upper Brahamaputra valley, distribution of G. kydia Roxb was recorded in 9 RFs and G. xanthochymus Hook.f. ex. T. Anderson was recorded from 8 RFs. IVI of these species in the forest is very less in number in comparison to the other plants and its abundance is mainly restricted to core forest areas where anthropogenic disturbance is very less. Associated plant species of Garcinia in Kukuramara RF was highest with 33 plant species and lowest in Tengani RF with 10 plant species.