Neonauclea sessilifolia

Neonauclea sessilifolia is a tree species in the Rubiaceae family. It is found in Taiwan, and then from Yunnan, Zhōngguó/China, to Southeast Asia and northeastern India.

Description
The tree grows some 7 to 30m tall, with a dark gray, transversely fissured and cracked bark, the inner bark is brown and sometimes mottled. The papery/thinly leather leaves are elliptic to elliptic-oblong or suborbicular in shape. The taxa is distinguished from other Neonauclea in China by having the following traits: the shape of the leaf blade, 6 to 9 pairs of secondary veins on the leaves with domatia in abaxial axils of the veins (occurring on the secondary, tertiary and even often on the quaternary veins); the corolla tuve is some 5-6mm. Flowers appear in October. The wood is whitish-grey, with a specific gravity of 0.7 g/cm3.

Distribution
The distribution of the species is slightly disjunctional, it grows in Taiwan, and then in a contiguous (clumped) area from Yunnan to Southeast Asia and northeastern India. Countries and regions where the plant grows are: Taiwan; Zhōngguó/China (Yunnan); Vietnam; Laos; Cambodia; Thailand; Myanmar; Bangladesh; and India (Assam, Eastern Himalaya).

Habitat, ecology
In Yunnan it grows in thickets or in angiosperm forests on hills, at altitudes from 500 to 800m. In Southeast Asia it grows in dense/closed and secondary forest.

The Renikhayong para Village Community Forest, Bandarban District, southeastern Bangladesh, is quite diverse, in 40 acres, there are 81 species of tree, in 35 families.
Euphorbiaceae species are most frequent (11 sp.), Rubiaceae next with 7 species, including the not very frequent Neonauclea sessilifolia. The forest is used by the neighbouring village for food and other material gathering, including charcoal making. Even though material is extracted from the forest, the locally managed high diversity is important for natural ecosystem conservation.

Vernacular names
无柄新乌檀, wu bing xin wu tan (Standard Chinese); 
ru'mliëy thôm (Khmer); 
kam gaas (Chakma, Bangladesh); 
kadam (Bandarban District, Bangladesh).

Uses
The wood is not very durable, in Cambodia it used for temporary constructions and the twig are used as firewood.
The Chakma people living in the Hill Tracts region of southeastern Bangladesh, use the leaves in their indigenous medicine to treat skin infections (leaf paste applied twice daily).

History
A prolific botanist, and very active academic, Elmer Drew Merrill first described the species in 1915, in his article "On the application of the generic name Nauclea of Linnaeus", published in the Journal of the Washington Academy of Sciences (Baltimore, MD).

Further reading
Choudhary, R.K., Srivastava, R.C., Das, A.K. & Lee, J. (2012). Floristic diversity assessment and vegetation analysis of Upper Siang district of eastern Himalaya in North East India Korean Journal of Plant Taxonomy 42: 222–246.
Govaerts, R. (2003). World Checklist of Selected Plant Families Database in ACCESS: 1–216203. The Board of Trustees of the Royal Botanic Gardens, Kew.
Wu, Z., Raven, P.H. & Hong, D. (eds.) (2011). Flora of China 19: 1–884. Missouri Botanical Garden Press, St. Louis.

References

sessilifolia
Category:Flora of Assam (region)
Category:Flora of Bangladesh
Category:Flora of Cambodia
Category:Flora of East Himalaya
Category:Flora of Indo-China
Category:Flora of Laos
Category:Flora of Myanmar
Category:Flora of Taiwan
Category:Flora of Thailand
Category:Flora of Vietnam
Category:Flora of Yunnan
Category:Plants described in 1915
Category:Taxa named by William Roxburgh