Platanthera pachycaulon (Hook.f.) Soó, Ann. Hist.-Nat. Mus. Natl. Hung.

Platanthera pachycaulon (Hook.f.) Soó, Ann. Hist.-Nat. Mus. Natl. Hung. View in CoL 26: 364. 1929. Habenaria pachycaulon Hook.f., Fl. Brit. View in CoL India 6: 154. 1890. Lectotype (designated by Efimov & Jin, 2014): INDIA , Sikkim, Nattong, 12.07.1877, King’s collectors 4345 (K [K000247394 digital image!]; isolecto CAL [CAL0000000796!]).

Platanthera exelliana Soó, Ann.Hist.-Nat. Mus. Natl. Hung. View in CoL 26: 359. 1929. Habenaria oligantha Hook.f., Fl. Brit. View in CoL India View in CoL 6: 154. 1890, non Turczaninow, 1854. Lectotype (designated by Efimov, 2016): INDIA View in CoL , Sikkim, s.d., Hooker 311 (K [K000247391 digital image!]).

Distribution: India , Bhutan, China, Myanmar and Nepal.

Specimens examined: INDIA , Arunachal Pradesh, Lohit district , Jachup, 29.08.1987, K . Haridasan 3730 ( OHT); West Kameng district, Poshing La, 21.07.1938, Kingdon-Ward 13960 ( BM digital image); Tawang district , Tawang , 29.07.2002, Bowes 15078 ( E digital image). Himachal Pradesh, Chamba District , Pangi , herb. Watt s.n. ( E digital image). Sikkim, s.loc., s.d., Hooker s.n. ( LE digital image); s.loc., s.d., Gammie s.n. ( K, P digital images); Patang La , 17.07.1877, King’s collector 4398 ( K digital image); Toksup, July 1887, King’s collector s.n. ( CAL); East Sikkim district , Changu, 13000 ft., 14.07.1956, Chatterjee’s collector 252 ( CAL); below Changu, 3750 m, 07.08.1997, A . Maity & S . K . Rai 18823 ( BSHC); near Changu, 12.06.1972, Tibetian Medicine Collector s.n. ( K digital image); Daphuk , on Kiuchin , 15000 ft., July 1888, King’s collector s.n. ( CAL); Jankra Inf., 05.08.1892, Gammie 625 ( BM, K digital images, CAL); Gnatung, 11000 ft., July 1894, Pantling 328 ( CAL); Jelep La, 08.07.1877, King’s collector 4202 ( K digital image, CAL); Kupup East side meadow, 4000 m, 19.09.1998, G . P . Sinha & B . K . Shukla 20509 ( BSHC); Kyangnosla Alpine Sanctuary , 3500 m, 25.06.2000, S . S . Dash 22773 ( BSHC); Ibid. , 3500 m, 28.06.2000, S . S . Dash 20974 ( BSHC); Nathula, 03.08.1877, King’s collector 4573 ( K digital image, CAL); North Sikkim district, Bijan, 1889, King’s collector s.n. ( CAL); Lachen, September 1849, Hooker & Thomson s.n. ( K digital image); Lachoong valley , July 1895, Pantling 327 ( BM digital image); Lachung, way to Shivmandir, 3861 m, 31.07.2019, K . Prasad 86534 ( CAL, BSID); Ibid. , 3868 m, 31.07.2019, K . Prasad 86536 ( CAL, BSID); Shingba Rhododendron Sanctuary , 3300 m, 06.08.2014, D. K . Agrawala 38894 ( BSHC); Ibid. , 3900 m, R . C . Srivastava s.n. ( BSHC); Shingba- Yumthang , 3688 m, 06.08.2014, D. K . Agrawala 38888 ( BSHC); Thangu , 3967 m, 31.07.2014, D. K . Agrawala 38850 ( BSHC); Yumtang, 24.07.1937, Lowndes 624 ( E digital image); Pakyong district : Natang , 02.09.1882, King’s collector s.n. ( CAL, BM digital image); Thanangi, 12000ft., September 1888, King’s collector s.n. ( CAL); West Sikkim district , Bikbari, Choktsering Chhu valley , 12.07.1992, Long et al. 303 ( E digital image); Dzongri , SE slope of Lapsa, 02.07.1983, Alpine Garden Society’s Expedition 278 ( K digital image); Ibid., 18.08.2017, S . Lahiri 73117 ( CAL); between Dzongri and Black Kabru, 18.07.1992, Long 452 ( E digital image); Jongri, 14000 ft., August 1896, Pantling 328 ( BM, K, P digital images, CAL); Ibid., 12.08.1913, Rohmoo Lepcha 956 ( E digital image); Kalijhal, Chewabhanyang, 3100 m, 19.06.2003, S . K . Rai & S . Pradhan 25042 ( BSHC); Toksup, near Jongri, July 1887, Pantling s.n. ( CAL); Yampung, 21.07. 1913, Rohmoo Lepcha 843 ( E digital image). Uttarakhand, Rudraprayag district , Mandani (dagla), 3645 m, 08.08.2014, I . D. Rai 11457 ( WII). West Bengal, Phullooh, 20.07.1884, King s.n. ( K digital image, CAL) .

Notes: This species was first described by Hooker (1890) under the genus Habenaria as H. oligantha (section Hologlossa ), a later homonym of H. oligantha Turczaninow, 1854 . Later, Soó (1929) shifted it to Platanthera and chose a different epithet, namely, P. exelliana . The type specimens of P. exelliana (= H. oligantha ) and P. pachycaulon (= H. pachycaulon ) are similar but distinguishable based on the number of sterile bracts and the shape of floral bracts ( Hooker, 1890). Since these features are not taxonomically significant, Efimov (2013, 2016) considered them as conspecific. This species was recently reported from Uttarakhand (western Himalaya) by Rai et al. (2014) and earlier it was only known from the eastern Himalayas. In the protologue, Hooker (1890) described the flowers as purple, but in the present study, it was found that they were green or greenish-yellow, which is the same as reported by earlier authors (Bose & Bhattacharjee, 1980; Chowdhery, 1998; Pearce & Cribb, 2002; Lucksom, 2007; Efimov, 2016). The purple colour may be an error due to changes caused by withering.