Didymocarpus nepalensis Bh.Adhikari & Mich.Möller, 2020

Didymocarpus nepalensis Bh.Adhikari & Mich.Möller View in CoL , sp. nov. Figs. 2 View Fig & 3 View Fig

Didymocarpus nepalensis is most similar to D. cinereus but

can be distinguished by the absence of basal leaves (vs.

present), inflorescences shorter than the stems (vs. equal to

longer) and calyx lobes 1/4–1/3 of the calyx tube (vs. half or

more than half).

Type: NEPAL, Dhankuta district, Pakhribas Municipality, Bokre , 27.08.2014, 1829 m, B . Adhikari , M . Kreuzer & R . Basnet 13 (holo E!; iso KATH!) .

Perennial herbs. Stems 7–17 cm long, appressed pubescent, hairs c. 0.1 mm long. Basal leaves absent, cauline leaves in lower half of the stem or near the middle in whorls of 3 or 4, those in upper half of the stem of same size and shape (if present) opposite, isophyllous to anisophyllous, ovate-elliptic, 4–7 × 0.8–5 cm, base cordate, apex obtuse, margins crenate, surfaces appressed pubescent with yellow sessile glands; uppermost cauline leaves 2–4, opposite-decussate isophyllous to anisophyllous, 1– 3.5 × 0.8–3 cm, base cordate, apex obtuse, margins irregularly crenate, surfaces appressed pubescent with bright yellow sessile glands; petioles 1–14 cm long, uppermost leaves usually sessile or shortly petiolate. Inflorescences 2–6, axillary in uppermost cauline leaves, pair-flowered cymes, flowers 2–6 per cyme; peduncles 1–5 cm long; pedicels 0.5–1 cm long, both glandular pubescent. Bracts in pair, free, ovate-lanceolate, 4.5–5 × 3–3.5 mm, densely glandular pubescent along margins and lower surface. Calyx dark purple, 5–7 mm, glandular pubescent with sessile glands; lobes 5, triangular, 1/4–1/3 of the length of the tube, 1–2 × 1–1.5 mm; tube 4–5 mm long. Corolla dark purple, 3–4 cm long, 2-lipped; upper lip 2-lobed, lobes ovatetriangular, 3–4 × 4–5 mm; lower lip 3-lobed, lobes ovate, 4–5 × 4–5.5 mm, glandular pubescent; tube infundibuliform, cylindric for c. 1 cm and gradually widening, slightly vertically compressed, appearing cylindrical from the side, opening oval. Stamens 2, inserted 2–3 cm from the base of the corolla; filaments 7–9 mm long, glabrous; anthers coherent, 3–4 × 1–2 mm, sparsely hairy. Staminodes 3, unequal, two laterals 4–6 mm long, middle one 2– 3 mm long. Disc cylindrical, 1.5–2 mm high, margins crenate. Pistils purplish green, 3–3.5 cm long; ovary cylindric, 2.5–3 cm long; style c. 0.5 cm long, glabrous; stigma capitate, slightly bilobed. Capsules 3–3.5 cm long, straight in relation to pedicel, valves straight to slightly curved, stipitate, glabrous. Seeds not seen.

Flowering & fruiting: Flowering from June to August and fruiting from July to August.

Habitat: On moist mossy cliffs in south facing forests dominated by Alnus nepalensis D.Don.

Distribution: Eastern Nepal.

Specimen examined: NEPAL, Dhankuta district, Pakhribas Municipality, Bokre , 27.08.2014, 1829 m, B . Adhikari , M . Kreuzer & R . Basnet 11 ( E, KATH) .

Conservation status: Didymocarpus nepalensis is known from one locality with two small populations in Dhankuta district of East Nepal. Each population consists of around 20–30 mature individuals. More extensive collections from eastern and central Nepal from similar habitats are needed to confirm its conservation status. However, there exist some threats as the populations are located near to a road and some species of Didymocarpus are collected by the locals to make incense. At present, it is best to be categorised as Data Deficient (DD) until more information on its uses, threats and status of population numbers becomes available.

Notes: Several Didymocarpus species from Nepal and adjacent areas in India are similar to the new species and possess violet to purple corollas ( Fig. 1 View Fig ). However, some have cylindric corolla tubes, such as, D. albicalyx ( Fig. 1e View Fig ), D. andersonii , D. macrophyllus Wall. ex D.Don , D. oblongus ( Fig. 1b View Fig ), D. primulifolius D.Don and D. villosus ( Fig. 1d View Fig ). Other species such as D. aromaticus ( Fig. 1a View Fig ), D. cinereus ( Fig. 1f View Fig ), D. pedicellatus ( Fig. 1c View Fig ), D. podocarpus C.B.Clarke and D. pulcher have similar infundibuliform corolla tubes but differ by other morphological characters: in D. pedicellatus the stem is very short (up to 1.5 cm) or absent. D. aromaticus and D. podocarpus are easily distinguished from any other and the new species by the position of their leaves; in D. aromaticus leaves are distant and alternate in the lower part of the stem whereas in D. podocarpus all leaves are crowded towards the apex of the stem. D. pulcher differs by its tall stems up to 45 cm, and 2-lipped calyx, and D. cinereus ( Fig. 1f View Fig ) differs by the characters given in Table 1. Similar to many other Didymocarpus species, but not all (e.g., Nangngam & Maxwell, 2013; Nangngam & Middleton, 2014; Pandey et al., this issue; Prasanna et al., this issue), D. nepalensis shows reciprocal enantiostyly, the deflection of the style and stamens to the left or right in opposite directions ( Fig. 2e View Fig ).