Spathoglottis, Blume, 1825

Tsering, Jambey & Prasad, Kothareddy, 2020, Spathoglottis arunachalensis (Orchidaceae), a new species from Arunachal Pradesh, India, Phytotaxa 432 (3), pp. 289-295 : 293

Key to the species of Spathoglottis in India :—

1. Scape and floral bracts glabrous; flowers usually purple; petals much broader than the sepals (more than 10 mm).......................... ............................................................................................................................................................... S. plicata Blume (1825: 401)

- Scape and floral bracts pubescent; flowers yellow; petals narrower than the sepals (less than 7 mm) .............................................2

2. Flowers 1.8–2 cm across; inner surface of sepals, petals and midlobe of lip with sparsely with minute hairs, margins of midlobe undulate, ridges of disk narrowly long rectangular, upper surface verrucose ............................................ S. arunachalensis sp. nov.

- Flowers more than 2 cm across; inner surface of sepals, petals and midlobe of lip glabrous; margins of midlobe entire, ridges of disk not as above ................................................................................................................................................................................3

3. Inflorescence less than 20 cm long; rachis 1 to 3-flowered; midlobe of lip without or with short claw ............................ S. ixioides

- Inflorescence more than 20 cm long; rachis laxly 2 to 8-flowered; midlobe of lip distinctly clawed ............................ S. pubescens