Thursday, May 6, 2021

[Botany • 2020] Didymocarpus sinoindicus (Gesneriaceae) • A New Species from India and China

 Didymocarpus sinoindicus N.S.Prasanna, Lei Cai & V.Gowda 

in Prasanna, Liu, Saryan, ... et Gowda, 2020. 
(photos by Lei Cai, De-Tuan Liu & Preeti Saryan). 

We describe a new species of Gesneriaceae, Didymocarpus sinoindicus N.S.Prasanna, Lei Cai & V.Gowda from India and China with detailed morphological description, diagnostic characters, illustrations, and colour photographs. The new species is morphologically similar to D. oblongus Wall. ex D.Don, D. hookeri C.B.Clarke, and D. adenocalyx W.T.Wang, but can be easily distinguished from them by its remarkable creamy-white to greenish-yellow sepals and petals and characteristic purple striations on corolla lobes.

Keywords: Kingdon-Ward, Nagaland, Northeast India, Saramati hills, Tengchong, Yunnan.

Fig. 1.  Didymocarpus sinoindicus N.S.Prasanna, Lei Cai & V.Gowda in India:
a. Habitat; b. Habit; c. Whole plant with inflorescence and infructescence; d. Inflorescence; e. Glands on the abaxial surface of leaves; f. Cyme with fruits; g. Young fruit
(photos by Preeti Saryan).  

Fig. 2.  Didymocarpus sinoindicus N.S.Prasanna, Lei Cai & V.Gowda in China:
 a. Habitat; b. Fruits; c. Plants with flowers and old fruits; d. Inflorescence and adaxial leaf surface; e. Mouth of a flower; f. Front view of corolla; g. Lateral view of flower showing calyx and bracts; h. Pistil with calyx and disc; i. Opened corolla showing internal structure; j. Stamens and staminodes
(photos by Lei Cai & De-Tuan Liu).  

Didymocarpus sinoindicus N.S.Prasanna, Lei Cai & V.Gowda, sp. nov.  

 Didymocarpus sinoindicus is morphologically similar to D. oblongus Wall. ex D.Don, but differs from it in having longer petioles (1.5–6.5 cm vs. 0.2–1.5 cm long), bicrenate or serrate leaf margins (vs. serrate to doubly serrate), and creamy-white to greenish-yellow (vs. purplish) corolla tube. It differs from D. hookeri C.B.Clarke in having shorter stems (2–8 cm vs. 4–17 cm long), and glabrous (vs. pubescent) corolla tubes. The new species differs from D. adenocalyx W.T.Wang in having glandular pedicels and calyces (vs. eglandular), and shorter corolla tubes (0.7–1 cm vs. c. 1.4 cm long).

Distribution: Currently, it is known from only two locations in India and one location in China, all of them bordering Myanmar. In India, the type locality is near the base camp of Mount Saramati in Kiphire district in the northeastern state of Nagaland. There is a historical collection site on the nearby Japvo ridge in Nagaland. In China, it is found in Danzha Village of Tengchong in Yunnan Province. It is likely to be present in the high elevation areas of Sagaing and Kachin states of northern Myanmar due to its similar habitat and proximity to the type locality. 

Etymology: The specific epithet ‘sinoindicus’ refers to the two collection localities from where the species has been collected and is known until now (China and India). It also acknowledges the serendipitous, simultaneous description of this species from two different research groups from India and China which happened to arrive at the same conclusions.

Prasanna N.S., Liu D.T., Saryan P., Duan S.Z., Cai L. and V. Gowda. 2020. Didymocarpus sinoindicus (Gesneriaceae), A New Species from India and China. Rheedea. 30(1); 135–142. DOI: 10.22244/rheedea.2020.30.01.07