Saturday, October 31, 2020

[Botany • 2020] Henckelia siangensis (Gesneriaceae) • A Remarkable New Species from Northeast India


Henckelia siangensis Taram, D.Borah & Tag 

in Taram, Borah, Taku & Tag, 2020.

Abstract
Henckelia siangensis, a new species from Arunachal Pradesh of Northeast India, is described and illustrated here. The new species is remarkably different from all other allied species by its 5-winged calyx and elliptic-ovate calyx segments. It superficially resembles H. calva in glabrous stem and petioles, but differs from it in having persistent bracts, a campanulate 5-winged calyx and a style with glandular indumentum. A detailed morphological description, photographic illustration, and distribution of the new species are presented.

Keywords: Arunachal Pradesh, flora of India, Himalaya, morphology, new taxon


Figure 1. Henckelia siangensis.
 A flowering stem B flower front view C flower side view (arrow indicates the bracteoles) D winged calyx (arrow indicates the wings) E dissected calyx segments F dissected corolla G stamens and staminodes H pistil (Photographs by Momang Taram).


Henckelia siangensis Taram, D.Borah & Tag, sp. nov.

Diagnosis: The species is remarkably different from all other species of Henckelia by its 5-winged calyx and elliptic-ovate calyx segments. It is superficially similar to H. calva (C.B.Clarke) D.J.Middleton & Mich.Möller in glabrous stem and petiole as well as lanceolate bracts, but can be easily distinguished by ovate to lanceolate lamina with denticulate to serrulate margins (vs. elliptic to oblong- elliptic with entire to sub-entire and ciliate margin), peduncle 0.4–0.8 cm, glabrous (vs. 2–3 cm long, glabrescent), bracts persistent (vs. deciduous), calyx segments elliptic to ovate, raised at margins forming wings (vs. narrowly triangular to lanceolate), corolla glandular pubescent inside (vs. glabrous) and glandular hairy style (vs. puberulent).
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Etymology: The species is named after the type locality, the Siang valley.

Vernacular name: (assigned here). Libe lirak Appun (in Adi language)

Distribution: So far only known from East Siang district of Arunachal Pradesh, India.

Habitat and ecology: It grows in moist shady places in rock crevices in association with Henckelia mishmiensis (Debb. ex Biswas) D.J.Middleton & Mich.Möller, Aeschynanthus superbus C.B.Clarke, Begonia josephii A.DC., B. burkillii Dunn., Elatostema sessile J.R.Forst. & G.Forst., Pilea umbrosa Blume, Nephrolepis cordifolia (L.) C.Presl., Selaginella sp. etc.
 

 Momang Taram, Dipankar Borah, Ojar Taku and Hui Tag. 2020. Henckelia siangensis (Gesneriaceae): A Remarkable New Species from Northeast India.  PhytoKeys. 160: 1-6. DOI: 10.3897/phytokeys.160.54459