Thunbergia nepalensis Bh.Adhikari & J.R.I.Wood

Adhikari, B., Pendry, C.A., Watson, M.F. et al. 2013. Kew Bulletin 68: 651. https://doi.org/10.1007/s12225-013-9481-x

Type

Type: Nepal, Doti, Ikeda H., Noshiro, S., Amano, M., Tanaka, T., Yamamoto, N., Pendry, C. A., Dell, B., Wang, Y., Bhatt, G. D. & Bhattarai, A. P. 20919006 (holotype E; isotype TI).

Morphology General Habit

Twining herb to c. 3 m

Morphology Stem

Stem terete, pubescent, the pubescence denser at nodes

Morphology Leaves

Leaves ovate, 5 – 8 × 2 – 5.5 cm, base truncate, shallowly cordate or hastate, apex acuminate, margin minutely dentate, palmately 5-veined, strigillose-pilose; petioles 1.5 – 3.5 cm

Morphology Reproductive morphology Flowers

Flowers solitary, arising from the axils of the upper leaves; pedicels 2 – 3.5 cm, glabrous; bracteoles pale green, ovate or oblong-ovate, 2 – 3 × 1 – 2 cm, apex acute, slightly pubescent to glabrous

Morphology Reproductive morphology Flowers Calyx

Calyx irregularly 5 – 7-toothed, rim c. 1 mm high, the teeth 1 mm long, ovate-deltoid

Morphology Reproductive morphology Flowers Corolla

Corolla white with yellow throat, glabrous, tube gradually widened from the base, 3 – 4 cm long and c. 1 cm wide at mouth, lobes rounded to shallowly retuse, oblong, or broadly obovate, 1 – 1.5 × 0.8 – 1 cm

Morphology Reproductive morphology Flowers Androecium Stamens Filaments

Filaments subequal, 10 – 12 mm, with tuft of hairs at base, anthers bearded, 5 – 6 mm, spurred, the spur 2 – 2.5 mm long

Morphology Reproductive morphology Flowers Gynoecium Ovary

Ovary glabrous, style 2 – 2.5 cm, stigma bilobed, lobes subequal-Capsule and seeds not seen

Note

Thunbergia nepalensis is similar in facies to T. fragrans but differs in its funnel-shaped corolla tube, 5 – 7 dentate calyx and spurred anther cells. The spurred anther cells and solitary flowers suggest an affinity with T. alata but there are only 5 – 7 ovate-deltoid calyx teeth, not 10 – 18 linear-subulate lobes and both stigma lobes are erect, not one spreading as in T. alata (Fig. 2N – P, Table 1). Thunbergia nepalensis looks similar to T. fragrans but differs by the spurred anthers and distinctive corolla tube which is not cylindrical but widened gradually towards the apex. The calyx is 5 – 7-toothed, not finely 12 – 17-toothed as in T. fragrans. The solitary flowers and spurred anthers suggest a relationship with T. alata but the corolla is white, never with a dark “eye”, the corolla lobes are much shorter than the corolla tube and the calyx teeth are fewer in number, ovate-deltoid in shape, not linear-subulate as in T. alata. The stigma of T. alata is ‘L’ shaped with unequal lobes (Fig. 2P) whereas in T. nepalensis the stigma lobes are subequal (Fig. 2C). The spurred anthers and inflorescence strongly suggest it should be included in subgen. ParahexacentrisBremek., a subgenus hitherto only known from Africa but a final decision should await examination of fruiting material.

Distribution

Endemic to western Nepal (Map 1).

Ecology

Degraded Alnusnepalensis forest, alt. 2100 m.

Conservation

Thunbergia nepalensis is so far known only from Doti and Bajura districts in the far west of Nepal. It is likely to be found in other similar habitats in the western Himalayas, and more extensive collections from the region are needed to confirm its distribution. It is, therefore, treated as Data Deficient (DD) until there is more comprehensive information about its distribution and the status of its populations.

Phenology

Found in flower during the monsoon from June to Aug.