Mentha choujunensis A. H. Ganie, Tajamul Islam & A. A. Khuroo, 2024

Ganie, Aijaz Hassan, Islam, Tajamul, Khuroo, Anzar Ahmad, Rasool, Nazima, Banoo, Sakina, Ali, Liyaqat & Reshi, Zafar A., 2024, Mentha choujunensis, a new species from Indian Trans-Himalayan region of Ladakh, Phytotaxa 666 (2), pp. 155-162 : 157-160

publication ID	https://doi.org/ 10.11646/phytotaxa.666.2.6
DOI	https://doi.org/10.5281/zenodo.14520348
persistent identifier	https://treatment.plazi.org/id/03BDBA2F-D643-FFDC-FF4C-8772FC161C2E
treatment provided by	Felipe
scientific name	Mentha choujunensis A. H. Ganie, Tajamul Islam & A. A. Khuroo
status	sp. nov.

Treatment

Mentha choujunensis A. H. Ganie, Tajamul Islam & A. A. Khuroo , sp. nov. ( Figures 2–4 View FIGURE 2 View FIGURE 3 View FIGURE 4 ).

Diagnosis:— The new species, M. choujunensis morphologically resembles with M. longifolia in few characters such as both having spicate inflorescence, spikes interrupted at lower side, linear bracts and bracteoles, campanulate calyx and corolla interior glabrous. However, it differs from M. longifolia in several characters which include: stem usually prostrate in M. choujunensis . (vs. stem erect in M. longifolia ), stem trichomes up to 3-celled (vs. up to 8-celled), leaves petiolate (vs. sessile to subsessile), leaf blade 3.2–3.7 cm long, ovate to ovate-lanceolate, base oblique, margin serrate (vs. 4.0–6.0 cm long, oblong-lanceolate, rounded to shallowly cordate, serrate-dentate), leaf trichomes 1-celled on adaxial side and 2-celled on abaxial side (vs. 3-celled on adaxial side and 4-celled on abaxial side), calyx less than half the length of corolla tube (vs. more than half the length of corolla tube), calyx 8–10-veined (vs. 5- veined), calyx teeth reddish-brown (vs. purplish), distal trichomes of calyx teeth long, 3–4-celled (vs. short, 3-celled), pedicel length up to 1.0 mm (vs. up to 2.0 mm), corolla white (vs. purplish), outer side of corolla eglandular (vs. glandular) ( Figure 4 View FIGURE 4 ).

Type:— INDIA. Ladakh, District Kargil, Suru valley (Choujun mountain), 34.539° N, 74.157° E, 3150 m, 2 July 2021, Aijaz H. Ganie, Tajamul Islam & Anzar Ahmad Khuroo 5671 (holotype: KASH, isotype: KASH).

Description:— Perennial, rhizomatous herb up to 60–70 cm tall. Stem prostate, quadrangular, much-branched, pubescent, trichomes acicular, 3-celled, warty. Leaves petiolate, petiole 0.3–1.1 cm long, leaf blade ovate to ovate-lanceolate, 0.5–3.7 × 0.4–1.7 cm, base oblique, margin serrate, apex acute, pubescent, trichomes sparse on adaxial side and dense on abaxial side, trichomes unicellular on adaxial side, wedge-shaped and 2-celled on abaxial side, acicular. Inflorescence verticillasters in cylindrical terminal spikes, 1.5–8.5 cm, spikes interrupted at lower side, 12–15 whorls per inflorescence, 20–30 flowers per whorl. Pedicel 0.5–1.0 mm long. Bracts simple, linear to oblong, smaller than leaves, decreasing toward apex. Flower sub-actinomorphic, 4–5 × 2–3 mm. Calyx campanulate, actinomorphic, 1.5–2.0 mm long, sepals 5, gamosepalous, free distally, 8–10-veined, pubescent on outer side, glabrous on inner side, triangular with purple distal ends, trichomes long, up to 4-celled. Corolla white, 3–4 mm long, petals ovate-lanceolate, pubescent on outer side, trichomes short and warty, upper petal 2-lobed, lower petals single-lobed, sub-equal. Stamens 4 in number, 5–6 mm long, exerted, anthers purplish to white in colour. Carpel 7–8 mm long, ovary up to 0.5 mm long, brownish green, glabrous, stigma exerted, bifid, lobes equal. Fruit sub-globular, reddish-brown, glabrous, upper half tuberculate.

Phenology:— Vegetative phase from May to June; flowering from July to September; fruiting from September to October.

Habitat:— The species prefers moist soils and grows along the southerly mountain slopes.

Chromosome number:— 2n = 2x = 24 ( Figure 3t View FIGURE 3 ).

Etymology:— The specific epithet ‘ choujunensis’ is derived from the Choujun mountain of Suru valley, district Kargil (Ladakh), India where from the taxon is described for the first time.