Pecteilis korigadensis Jalal & Jayanthi, 2019

Jalal, Jeewan Singh & Jayanthi, Janakiraman, 2019, Pecteilis korigadensis (Orchidaceae: Orchidoideae), a new terrestrial orchid from the northern Western Ghats, India, Phytotaxa 388 (2), pp. 167-173 : 169-170

Pecteilis korigadensis Jalal & Jayanthi , sp. nov. ( Figs. 1–4 )

Type:— INDIA . Maharashtra: Pune District, Korigad-Aamby Valley , 640 m elev., 29 September 2018, Jalal & Jayanthi 197752 (holotype; BSI) .

Pecteilis korigadensis differs from P. gigantea , P. henryi , P. susannae and P. triflora in having cauline leaves with large conspicuous flowers and long spurs, a trilobed lip with lateral lobes spreading, denticulate on one margin with few lacerations towards apex and midlobe shorter than lateral lobes.

Terrestrial herbs, up to 50 cm high (including inflorescence). Tubers 2, oblong, 4.0–5.0× 1.5–2.0 cm, roots 8, 0.5 cm thick. Stems erect, leafy throughout, 2–3-sheathed at base. Leaves 7, alternate, variable in size, basal leaves smaller, becoming larger at slightly below middle of stem, ovate to lanceolate, 3.5–14.5 × 1.8–3.5 cm, acute at apex, margin entire, sheathing and amplexicaul at base, midnerve prominent beneath, with 3 parallel veins on each side. Inflorescence a terminal raceme, 8 cm long, 6-flowered; peduncle 2 cm long, covered by large sterile bracts at base. Sterile bracts 5, foliaceous, lanceolate, 5.0–7.5 × 1.4–1.5 cm, apex acuminate, margin entire, sheathed at base. Floral bracts lanceolate, 4.2–5.2 × 0.8–1.4 cm, acuminate with filiform apex, margin entire, shorter than to slightly exceeding ovary. Flowers white, 5 cm across; pedicel 2 mm long; ovary fusiform, 4.8 cm long, ribbed, arching from stem, swollen and green at lower portion, pale green-white at apex. Sepals free, spreading; dorsal sepal erect, broadly elliptic-ovate, cymbiform, 2.0 × 1.8 cm, acute at apex, margin entire, prominently 3-green veined, lateral veins further divided into 3- veinlets; lateral sepals obliquely ovate, 2.5 × 1.5 cm, margins rolling backwards, 3-veined, lateral veins further divided into 3-veinlets. Petals erect, close to edges of dorsal sepal, linear-oblong, 2.0 × 0.3 cm, acute at apex, margin entire, 2-veined. Lip spurred, trilobed, claw 5 × 6 mm, midlobe linear, 3.5 × 0.2 cm, pointing downwards, slightly curved at tip, shorter than lateral lobes, lateral lobes narrow, 4.5 × 0.3 cm, longer than midlobe, spreading upwards, at almost 900 angle with midlobe, tridenticulate along upper margin, entire along lower margin with 2–3-filiform apical lacerations. Spur 11 cm long, green throughout, subclavate, much longer than ovary, mouth of the spur W-shaped with a ligule at opening. Column erect, broadly oblong, 5 × 7 mm, white, subretuse at apex, with rostellar arm, anther locules widely spaced on a broad connective. Rostellum 2.5 × 4.0 mm, with rugose gland on each side. Stigma beneath the rostellum. Pollinia 2, 1.3 cm long; pollinium yellow, 4 mm; caudicle 8 mm; viscidia 2, white, globose, 1 mm. Fruits not seen.

Flowering:— September–October, at the end of the monsoon season (end of September to first week of October).

Distribution:— Known only from the Aamby Valley, Pune District ( Fig. 1 ).

Habitat & Ecology:— Open grassy slopes of semi-evergreen vegetation at 640 m elevation. In this habitat, several other orchid species can be found, including Habenaria longicorniculata Graham (1839: 202) , Pecteilis gigantea , and Eulophia spectabilis ( Dennstedt 1818: 38) Suresh (1988: 300) . Other herbaceous species are species of Impatiens , Desmodium , Smithia , Curcuma , grasses etc. This habitat has characteristic red soil that remains humid for some period during rainy season (June to mid October) and completely dries up during the summer (November to May).

Etymology:— Named after the type locality, which is well known for the famous Korigad Fort, a place of historic importance associated with Maratha ruler, Chhatrapati Shivaji Maharaj.

Threats:— Restricted to a small area threatened by local grazing, trampling and invasive species. Some possible threats in the near future are expansion of agriculture because the habitat is near fields. This species is found growing with the elegant species, Pecteilis gigantea , the flowers of which are used for decoration during the Ganpati festival by the local villagers. There would be a high possibility of plucking this orchid also due to its large size and attractiveness. Based on what is currently known, the species is extremely rare. Only a single plant was sighted at a single locality. However, more exploration is needed in similar habitats to assign the exact threat category. However, based on its limited range and potential threats observed, it is provisionally assessed as critically endangered B1a using the IUCN criteria (2012).

Notes:— This species could be easily mistaken for a species in the closely related Habenaria , but it can be distinguished from Habenaria by the following features: presence of a broad, fleshy rostellum with a rugose gland on each side above the stigma lobes and stigma beneath the rostellum with lobes not extending from the column. Pecteilis korigadensis is not directly allied to any of the species to which it is morphologically comparable. This species can be readily recognized by its large flower and spur size and tripartite lip with spreading, narrow lateral lobes and a few filiform lacerations.

Figures

FIGURE 1. Distribution of Pecteilis korigadensis in Maharashtra.

FIGURE 2. Pecteilis korigadensis in its natural habitat with inflorescence details.

FIGURE 3. Pecteilis korigadensis. A. Habit. B. Front view of flower. C. Side view of flower showing bract, ovary and spur. D. Dorsal sepal. E. Lateral sepal. F. Petal. G. Lip. H. Column, ovary and spur. I. Column. J. Side view of column. K. Pollinia. Photographs by J. Jayanthi & J.S. Jalal.

FIGURE 4. Pecteilis korigadensis. A. Habit. B. Front view of flower. C. Side view of flower showing bract, ovary and spur. D. Dorsal sepal. E. Lateral sepal. F. Petal. G. Lip. H. Column, ovary and spur. I. Column. J. Pollinia. Drawing by J.S. Jalal.