Taxonomic revision of Habenaria josephi group (sect. Diphyllae s. l.) in the Pan-Himalaya Author Pandey, Tirtha Raj https://orcid.org/0000-0002-9081-8409 State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China & University of Chinese Academy of Sciences, Beijing 100864, China & National Herbarium and Plant Laboratories, Godawari, Lalitpur, Nepal Author Jin, Xiao-Hua State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China xiaohuajin@ibcas.ac.cn text PhytoKeys 2021 2021-04-06 175 109 136 http://dx.doi.org/10.3897/phytokeys.175.59849 journal article http://dx.doi.org/10.3897/phytokeys.175.59849 1314-2003-175-109 9BC1BDC81BE0520E819ED60BD77AAE73 1. Habenaria josephi Rchb. f., Trans. Linn. Soc. London, Bot., ser. 2, 3: 114 (1888). Habenaria aitchisonii josephi ≡ Habenaria aitchisonii var. josephi (Rchb.f.) Hook.f., Fl. Brit. India 6: 152 (1890). Habenaria diphylla josephi ≡ Habenaria diphylla var. josephi (Rchb.f.) N. Pearce & P.J. Cribb, Edinburgh J. Bot. 58: 114. 2001. Type. INDIA, Sikkim, 1849, J.D. Hooker 42 [holotype: K (K000247480 image!); isotypes: K, AMES (00256484 image!), P (P00370608 image!), LE n.v.]. Habenaria clarkei Habenaria clarkei Kränzl., Bot. Jahrb. Syst. 16: 148 (1892). Type. INDIA, Sikkim, J. D. Hooker 42 [lectotype designated here: K (K000247480 image!); isolectotypes: K, AMES (00256484 image!), P, LE n.v.]. Description. Terrestrial herbs, 5-20 cm tall. Tubers ovoid-fusiform. Stems pubescent. Leaves 2, opposite, basal; sheathing at base; leaf blade broadly ovate-orbicular to weakly cordate, 1.5-3.1 cm long, 1-2.5 cm broad, apex apiculate. Inflorescences 4-15 cm long, laxly to subdensely 2- to 6-flowered; rachis minutely glandular, pubescent, 1.5-3.8 cm long; floral bracts narrowly lanceolate, ca. 1 cm long, pubescent, apex acuminate. Flowers green, fragrant; ovary and pedicel curved, 7-13 mm long, pubescent. Dorsal sepal ovate, 5.5-6 mm long, 2.5-3 mm broad, apex acute, forming hood with petals; lateral sepals ovate, reflexed to spreading, 5-7 mm long, ca. 2.6 mm broad, apex acute. Petals obliquely ovate-triangular, base broad, 5-6 mm long, 2-2.5 mm wide, apex acute; lip 3-lobed, clawed, spurred; lateral lobes linear, apex recurved-coiled, 6-9 mm long, ca. 0.6 mm wide; mid-lobe linear, ca. 5 mm long, ca. 0.5 mm broad; spur curved, clavate, 8-15 mm long. Column stout; anther locules parallel; pollinia globose-ovoid; caudicle stout; stigma processes closely parallel, united above mouth of spur, lingulate. (Fig. 4 ). Figure 4. Habenaria josephi A habit B floral bract C pedicellate ovary with spur D petal E dorsal sepal F lateral sepal G lip ( A photographed from FLPH Expedition 13-0845 , PE B-G drawn from the same specimen by T.R. Pandey). Phenology. Flowering from July to September. Habitat. Moist grassy hillsides, stream banks, in Betula forest; 3000-4600 m elev. Distribution. Endemic to the Pan-Himalaya; Sikkim and Darjeeling, Bhutan, M Yarlung Zangbo, Yarlung Zangbo-Brahmaputra and S Hengduan. (Fig. 5 ). Figure 5. Distribution of Habenaria josephi (black circles) in the Pan-Himalaya. More illustrations. Pearce and Cribb (2002 , fig. 41, a-m; as H. diphylla var. josephi ). Additional specimens examined. SIKKIM and DARJEELING: Sikkim , Tungu, 3648-3952 m elev., 1849, J.D. Hooker 42 (K). BHUTAN : Bumthang , Marlungm Tsampa, 4400 m elev., 1949, F. Ludlow , G. Sherriff & J.H. Hicks 19397 (AMES 01946674); Gasa , Upper Mo Chu , 4120 m elev., 1984, I.W.J. Sinclair & D.G. Long 5289 (RENZ); Gasa , Gafoo-la, Upper Pho Chu , 4000 m elev., 1949, F. Ludlow , G. Sherriff & J.H. Hicks 16725 [CAL (CAL0000056823), AMES (01946675)]; Jomolhari (GLORIA site), 4514 m elev., 2010, S. Den et al. 193 (National Biodiversity Centre, Bhutan). M YARLUNG ZANGBO: Yadong , Phari, 1879, Dungboo s. n. [K (K000247481), CAL (CAL0000092705)]; Yadong , North of Phari , 1882, Dr. King's collectors s. n. (CAL0000092702); Yadong , Tem-la, North of Phari , 1882, G. King's collectors s. n. (CAL0000092703). YARLUNG ZANGBO-BRAHMAPUTRA: Cona , 3641 m elev., 2013, FLPH Tibet Expedition 13-0957 (PE); Zayü , 4100 m elev., 2013, FLPH Tibet Expedition 13-0845 (PE). S HENGDUAN: Yulong , eastern flank of Lichiang range, 3500 m elev., 1906, G. Forrest 2739 (CAL0000055843) . Note. Hooker (1890) tentatively placed some of the Habenaria species, such as H. reniformis (D. Don) Hook.f., H. diphylla Dalz. and H. aitchisonii Rchb.f., into the section Habenaria Trimeroglossa . However, H. josephi was assigned a varietal rank under H. aitchisonii . Later, Kränzlin (1892 , 1901 ) proposed the section Habenaria Diphyllae to accommodate the species with two basal leaves and included H. clarkei , H. glaucifolia , H. diphylla , H. reniformis and H. aitchisonii in the section along with a few other Habenaria species. He followed Hooker's view regarding the position of H. josephi as a variety of H. aitchisonii , albeit with a note " Die var. Josephi Hook. f. ist nur eine Form , aus den hoechsten der oben angegebenen Standorte stammend (the variety Habenaria josephi is only a form occurring in the highest of the above-mentioned locations)" suggesting that the plant is merely a higher elevation variety of H. aitchisonii . Paradoxically, Kränzlin described H. clarkei in the same publication, based on a duplicate of Hooker 42 (the type specimen of H. josephi ) from Sikkim, which was kept at B (distributed from Hooker's Herbarium at K). After an extensive search, it now appears that Hooker 42 had at least six duplicates: two at K and one each at P, AMES, B and LE, of which the specimen at B was lost during the Second World War, while at LE, the specimen could not be found during a recent search (fide Petr Efimov). The remaining four duplicates are still extant. In the past, the taxonomic identity of Habenaria josephi became doubtful, often shifting from one name to another, sometimes as Habenaria aitchisoni var. josephi (Rchb.f.) Hook.f. or as H. diphylla var. josephi (Rchb.f.) Pearce & Cribb. Even in recent literature on the orchid species of Sikkim, its type locality is not uniform in this regard. Some botanists treat it as a variety of H. diphylla ( Pearce et al. 2001 ; Pearce and Cribb 2002 ; Lucksom 2007 ; Choudhury et al. 2011 ), while Maity et al. (2019) regard it merely as another synonym of H. diphylla . A closer look at this species reveals it to be not only distinct morphologically, but also well characterised in terms of habitat and distribution. Whereas H. diphylla is predominantly a tropical species of moderate size (10-40 cm tall), broadly distributed from peninsular India to the Philippines, H. josephi is a small-sized (5-20 cm tall) high-elevation temperate to alpine species occurring from Sikkim eastwards to the Hengduan Mountains, i.e. it is endemic to the Pan-Himalaya. Pearce et al. (2001) provided an elaborate discussion on the phenetic variations that delineate this taxon from the other species, yet they assigned it to a varietal rank under H. diphylla . Examination of the type and other dried specimens, as well as living individuals, clearly shows that it is distinct. Short stature, scape without sterile bracts, 2-6-flowered rachis, curved, pubescent ovary, deflexed lateral sepals and lip with stooping (reflexed) lateral lobes that ultimately coil around terminally are amongst the unique diagnostic morphological features. Furthermore, recent molecular studies ( Jin et al. 2017 ; Raskoti and Ale 2019 ) have consolidated its distinction from similar-looking species. Therefore, a specific rank seems fully justified here.