Oberonia bopannae Chowlu & Kumar, 2017

Chowlu, Krishna, Malik, Saloni, Kumar, Pankaj & Babbar, S. B., 2017, Oberonia bopannae (Orchidaceae: Epidendroideae: Malaxideae: Malaxidinae), a new species from Arunachal Pradesh (India), Phytotaxa 316 (3), pp. 285-291 : 287-289

Oberonia bopannae Chowlu & Kumar sp. nov. ( Fig. 1 , 2 )

Type:— INDIA . Arunachal Pradesh: Namsai District, Tengapani, 02 October 2014, K. Chowlu 40001 (Holotype CAL!).

Diagnosis: Oberonia bopannae shows close affinity to O. gammiei and O. mucronata , but they can be differentiated on the basis of shorter stem (2.5–3.5 cm); triangular-ovate floral bract; ovate sepals with acute apex; labellum squarish, i.e., length and width same; lacinations shorter at the junction of mid lobe and side lobe in O. bopannae against longer stem (4.0– 5.5 cm); oblong floral bract; ovate-oblong sepals with obtuse apex; labellum length greater than width giving a rectangular look; absence of lacinations at the junction of mid lobe and side lobe; unipinnate lacinations in O. gammiei and shorter stem (2.0–3.0 cm long); floral bract ovate-lanceolate; sepals ovate, obtuse; labellum rectangular; lacination continuous throughout the margin and of same length except the apex; lacinations unipinnate.

Description: Herbaceous epiphyte. Roots 1–1.5 mm thick, up to 10–20 cm long. Stem 2.5–3.5 cm long. Leaves jointed, 4–5, 3.5˗21×1.0– 2.2 cm, broadly oblong˗lanceolate, ensiform, arcuate (curved outwards abaxially from middle), minutely falcate. Inflorescence curved or drooping; peduncle 7–8 cm long, terete, broadly winged, with many sterile bracts towards the apex; rachis up to 19 cm long, densely many flowered, flowers arranged it in whorls; floral bract c. 1.5 × 0.5 mm, triangular˗ovate, acute to sub˗acute, minutely serrate. Flowers 1.7–2.0 mm across, widely opening, orange˗pale green, arranged in whorls. Sepals and petals ca 1 mm long, ovate oblong, obtuse to subacute, deflexed on the ovary. Petals serrate to minutely lacinate. Lip2.5 × 2.5 mm, giving a square shaped look, deeply lacinate throughout the margin except at the junction of mid and side lobes, lacinations tripinnate, brownish-yelllow, epichile forked like two lobules orbilobulate; lobules of mid-lobe quadrate, divergent, deeply lacinate, fimbriate. Column c. 0.5 mm long. Operculum pale yellow. Pollinia pyriform, yellow.

Flowering: October–November.

Etymology: The specific epithet bopannae is given in honour of Lt. Gen. B.K. Bopanna PVSM, AVSM, VSM (Retd.) and former Director General, National Cadet Corps (NCC) who is a great orchid lover and enthusiast.

Distribution: India (Arunachal Pradesh).

Habitat ecology: Oberonia bopannae grows on moss covered tree trunk of small and large trees in tropical wet evergreen forest at an altitude of about 151 metres, in association with other epiphytic orchids, viz. Pholidota sp. , Dendrobium sp. along with some ferns.

Conservation assessment: Around 10 individuals were observed constituting a small population of Oberonia bopannae at the site at a single locality of Tengapani (Namsai District, Arunachal Pradesh) in a wet evergreen forest. Namsai district has been newly constituted and it is expected to undergo lot of developmental changes, posing immense threat of habitat loss or degradation of habitat for this species. Area of occupancy and extent of occurrence are less than 10 km 2 and hence we assess this species as Critically Endangered (B1+B2ab(iii); D) ( IUCN 2012).

Figures

FIGURE 1. Oberonia bopannae Chowlu & Kumar sp. nov. A. Habit; B. Part of Inflorescence; C. Floral bract; D. Flower; E. Dissected parts; F. Lip (original structure); G. Column with pedicel ovary; H.Anther cap; I. Pollinia.

FIGURE 2. Oberonia bopannae Chowlu & Kumar sp. nov. A. Lip (after stretching); B. Lip (normal).