Wednesday, June 24, 2020

[Botany • 2020] Rhynchotechum nirijuliense (Gesneriaceae) • A New Species from Northeast India

  Rhynchotechum nirijuliense Taram & D.Borah

in Taram & Borah, 2020. 
 Gardens' Bulletin Singapore. 72(1)

A new species of Rhynchotechum (Gesneriaceae), Rhynchotechum nirijuliense Taram & D.Borah, is described from Nirijuli of Papum Pare district in Arunachal Pradesh, Northeast India. The new species is compared to Rhynchotechum ellipticum and R. calycinum. A detailed description, colour photographs and notes on the distribution and ecology of the new species are provided.

Fig. 1.  Rhynchotechum nirijuliense Taram & D.Borah.
A. Habitat and habit. B. Adaxial surface of leaf. C. Abaxial surface of leaf. D–F. Inflorescences, showing the axillary arrangement of the cymes. G. Side view of a branch of the inflorescence. H. Dissected floral parts. I. Fruit. (Photos: D. Borah)

Rhynchotechum nirijuliense Taram & D.Borah, sp. nov.

Rhynchotechum nirijuliense is most similar to R. ellipticum in plant height, arrangement and shape of leaves, young parts woolly pubescent, reduced or absent peduncle and narrowly triangular calyx lobes, and to R. calycinum in overall leaf shape, denticulate lamina margin, inflorescence length and villous branches, but differs from both in the generally shorter petiole, more numerous secondary veins, more villous calyx lobes, longer style and larger berries (see Table 1).

Etymology. The specific epithet refers to the place where the new species was found.

Notes. Rhynchotechum is an Asian genus and half of the species are distributed in India (mostly Northeast India). Characters such as inflorescence size, style length and shape of the berries are very useful in the delimitation of species (Anderson & Middleton, 2013). Apart from the new species described here, the other species of Rhynchotechum found in the state are R. ellipticum, R. calycinum, R. parviflorum, R. vestitum and R.obovatum.

M. Taram and D. Borah. 2020. Rhynchotechum nirijuliense (Gesneriaceae), A New Species from Northeast India. Gardens' Bulletin Singapore. 72(1); 125–129. DOI: 10.26492/gbs72(1).2020-12