Aconitum haridasanii Raghuvar Tiwary, Harsh Singh & D. Adhikari, 2020

Aconitum haridasanii Raghuvar Tiwary, Harsh Singh & D. Adhikari View in CoL , sp. nov. ( Fig. 1–4 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 )

Aconitum haridasanii differs from its closely allied species Aconitum spicatum in flexuous nature of the stem (vs. straight), upto 2 m height (vs. upto 1 m), pale yellow to white colour of flower (vs. blue), length of inflorescence upto 10 cm (vs. upto 25 cm), 15–17 mm long petals (vs. 10–12 mm long) and 3 carpels (vs. 5 carpels) ( TABLE 1 View TABLE 1 ).

TYPE:— INDIA. Arunachal Pradesh, Tawang, towards Taktsang Chu lake , 27.723656° N; 92.023457° E, 3798 m a.s.l., 20 September 2018, Raghuvar Tiwary, Harsh Singh, Prem Prakash Singh & Dibyendu Adhikari 303752 (holotype LWG GoogleMaps ; isotype LWG GoogleMaps ).

Description

Biennial herb; roots paired, tuberous, fusiform; daughter-tuber conic, 5–6 cm long with fibrous root. Stem 1–2 m high, erect but flexuous above, simple, terete, hairy, hairs appressed and deflexed. Leaves both radical and cauline; radical leaves withered at anthesis, when present petiolate, petiole 5–7 cm long, leaf-blade thinly coriaceous, lamina 4–9 cm x 3–10 cm; cauline leaves petiolate, petiole 4–6 cm long, sheathing with dilated bases, pentagonal, 3–8 cm x 3.4–7.0 cm, 3 deep divisions 3–10 mm from base, central lobe rhombic, dissected twice to thrice, ultimate lobe oblong-triangular, apex acuminate, margin entire, base rounded, lateral lobes obliquely flabellate, unequally 2- parted. Inflorescence paniculate, ca. 10 cm long, (2–) 4–8 flowered, bracts leaflike; 1.5–2.0 mm × 1.5–1.6 mm, ovate, rachis appressed, densely hairy, pedicels 1–4 cm long, with 2 linear or subulate bracteoles nearly at middle, bracteoles linear to lanceolate, apex acuminate. Flowers pale yellow to white; sepals 5, divided into three parts, one upper sepal helmet shaped, 1.6–1.8 cm long, 1.0– 1.1 cm wide, obliquely obovate in profile, not clawed, beaked, pubescent; beak prominent, 1 to 2 mm long, not pointed, terminally directed upward, margin entire, apex acuminate; two lateral sepals, ca. 1.3 × 1.2 cm, obliquely sub-rounded; lower sepal ca. 1.2 × 0.8 cm, elliptic, margin entire. Petals 2, 0.4–0.5 cm long, hispidulous; claws 0.2–0.3 mm long, forward leaning, hood sub-horizontal, gibbous at back; lips short and widened toward base, 2.5 × 3.1 mm, terminally roundish, broad, emarginated and bilobed. Stamens 4–5 mm long, many; filament densely pubescent on the upper part, golden hairs, 5.5–5.8 mm long membranous, anther glabrous or slightly pubescent, 0.9 mm × 1.2 mm, globose. Carpels 3, 6.2 mm × 1.3 mm, ovaries sparsely appressed, pubescent, 3.7 mm long; style 2.5 mm long, stigma persistent. Follicles oblong, 1.5–1.8 cm long.

Flowering and Fruiting: —Flowering observed from August to September; fruits mature in October.

Etymology: —The specific epithet ‘haridasanii’ is derived from Dr. Krishnankutty Ezhuthachan Haridasan’s name to honor his immense contribution towards the flora of North-East India.

Conservation status: —The genus Aconitum was surveyed extensively in the Eastern Himalayan region and north-east India from 2016 to 2018. The Extent of Occurrence (EOO) for A. haridasanii was only 0.13 km 2 and Area of Occupancy (AOO) was 0.02 km 2. Two populations were located in the Shuguster lake and Taktsang Chu area at an elevation range of 3678–3798 m. Extreme year to year fluctuation in the number of individuals was recorded during the study period. The habitat of the species is threatened by habitat fragmentation, tourism, road construction and other development activities. The grazers and shepherds also selectively uproot the species from pastures to prevent accidental cattle poisoning and death. The extraction of the species owing to its medicinal importance is another key factor for its population depletion. All these factors have contributed to the very low population size of the species. The number of matured individuals in both populations ranged from 15–20 individuals i.e., <50 individuals ( TABLE 2 View TABLE 2 ). The new species was categorized (following IUCN 2017 version 13) as Critically Endangered B1b(i,ii,iii,v)c(i,ii,ii i)+2b(i,ii,iii,v)c;C2a(i);D ( TABLE 3 View TABLE 3 ).

Additional specimens examined: — INDIA. Arunachal Pradesh, Tawang, towards Shuguster lake , 27.713937° N; 91.833731° E, atl. 3678 m a.s.l., 20 September, 2018, Raghuvar Tiwary, Harsh Singh, Prem Prakash Singh & Dibyendu Adhikari 303753 GoogleMaps .