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 ).