Swertia pseudohookeri Harry Sm., Bull. Brit. Mus.

Swertia pseudohookeri Harry Sm., Bull. Brit. Mus. View in CoL (Nat. Hist.), Bot. 4: 246.1970; Ohba & Akiyama, Alp. Fl. Jalijale Himal. 51. 1992. Type: BHUTAN, Marlung , Tsampa, 4400 m, 12.07.1949, F. Ludlow, G. SherrifF & J.H. Hicks 19414 (holo BM [ BM001014596 ] digital image!; iso UPS [UPS BOT V-139957] digital image!). Figs. 2 View Fig & 3 View Fig

Perennial herbs to 60 cm tall. Roots tuberous, yellow. Stems erect, firm, hollow, terete, smooth, green. Basal leaves rosette, many, membranous; petiole c. 6 cm long; blade elliptical, subacute, 8–16 × 6–8 cm, gradually reduced on the enlarged petiole, margins entire; upper leaves smaller than basal leaves, ovate, sessile, membranous, subacute, 6–10 × 4–7 cm, decreasing upwards, opposite in pairs at nodes. Inflorescences narrowly pyramidal, loose, green, branched from base node up to middle part of stem; upper part not branched, flowers in whorls as well as one flower in solitary position. Flowers tetramerous, c. 2 cm in diam., white-green with purple-stripes denser towards margins; pedicel 1.5–5 cm long, glabrous, slightly winged, green; calyx tube c. 2 mm long, pale green, lobes obtuseovate, c. 11 × 7 mm, margins entire; corolla tube c. 4 mm, lobes wedged, apex truncate and slightly erose, c. 2 × 0.8 cm; nectary 4, one per petal at the base with long greenish-white fimbriate in between insertion of filaments, oval or rhomboid, c. 3 mm. Stamens attached to corolla tube, filaments free, c. 7 mm long, dark green, anthers c. 2 mm long. Ovary ovoid, glabrous; style indistinct; stigma round, small, white. Capsule not seen.

Flowering & fruiting: Flowering from July to August and fruiting from September to October.

Habitat:This species is predominantly found in grazing meadows or scrubs of alpine regions in association with Primula spp. ( Primulaceae ), Rhododendron spp. ( Ericaceae ), Pedicularis sp. ( Orobanchaceae ), Potentilla sp. ( Rosaceae ), and others.

Distribution: Bhutan, Nepal and now in India.

Specimen examined: INDIA, Arunachal Pradesh, Tawang , 4103 m, N 27°38’54.1026”, E 91°52’1.686”, 15.07.2023, B. Hajong BAR-003 (12898, 12899 CSIRNEIST) GoogleMaps .

Notes: This species is endemic to the central and eastern Himalayas, displaying distinctive characters such as an erect, perennial herbaceous habit, cymose inflorescence, large greenish-white purple-striped corollas and rhomboidal or oval nectaries with raised fimbriae surrounding the small adaxial opening of the nectaries. Notably, the presence of fimbriae is a feature shared with Swertia splendens , which also is found in Arunachal Pradesh. However, S. pseudohookeri can be easily distinguished from S. splendens , by its ovate leaves (vs. spatulate to obovate), green stems (vs. brick red), greenish-white and purple-striped flowers (vs. brick red, when drying yellow-green) and nectary with long fimbriae (vs. short) ( Fig. 4a View Fig ). Another species, S. grandiflora , has been sighted in two localities, Se La and Bangajaan, and was first documented in India in 2020 ( Bharali et al., 2018; Liden & Bharali, 2020). S. pseudohookeri shares some similarities with S. grandiflora such as the perennial erect habit with single robust stem, large tetramerous flowers (3–4 cm in diam.) with one nectary per corolla lobe, but can be easily distinguished by its green stems (vs. brick red),

greenish-white and purple-striped flowers (vs. reddish-green) and nectary with long fimbriae (vs.

short) ( Fig. 4b View Fig ).