A new species of Zingiber (Zingiberaceae) from Natma Taung National Park, Chin State, Myanmar

Abstract Zingiber natmataungense S.S.Zhou & R.Li (Zingiberaceae), a new species from Natma Taung National Park, Chin State, Myanmar, is described and illustrated. The new species is morphologically similar to Z. yunnanense, but differs by: leaf blade abaxially light green, glabrous, ligule sparsely pubescent, ca. 2–3 mm, bracts glabrous; calyx white 20–21 × 3.2–3.5 mm, glabrous, apex obviously 3-toothed; corolla tube white, ca. 3.9–4.1 cm, labellum lateral lobes, ca. 1.5–1.7 × 0.6–0.7 cm; stamen with sparse pubescent, filament white, glabrous, 1–2 mm; anther connective appendage yellowish proximally, purplish distally; ovary white, sparsely white pubescent, epigynous glands, ca. 6–7 mm long, tapered, apex whorled, yellow. This new species is also similar to Z. teres, but has a different flower colour.


Introduction
Zingiberaceae is a pantropical and subtropical family, but with most species distributed in South and Southeast Asia. Zingiberaceae consist of about 50 genera and 1300 species. There are about 100 to 150 species in Zingiber, out of which 42 occur in China (Wu and Larsen 2000). Plants of the genus Zingiber are widely used throughout the world as foods and as herbal remedies in various traditional healing systems because of their wide range of bioactivities (Sharifi-Rad et al. 2017). In the last decade, one new genus and several new species of Zingiberaceae have been described from Myanmar (Kress et al. 2010;Gowda et al. 2012;Ding et al. 2018;Tanaka and Aung 2019). Two new species of Zingiber were reported recently from the west and northwest of Myanmar Tanaka and Aung 2017). Plant diversity in Myanmar has certainly been underestimated so far and there is an urgent need for both botanical exploration and plant conservation (Jin et al. 2018).
Since 2014, cooperation between the Ministry of Natural Resources and Environmental Conservation in Myanmar and the Chinese Academy of Sciences (CAS) has resulted in more than ten joint biodiversity investigations in northern and western Myanmar by researchers from the Forest Department of Myanmar and CAS institutions. During our investigations from October 2016 to July 2019, in Natma Taung National Park, Chin State, western Myanmar, a new species of Zingiber was discovered and is described as follows.

Materials and methods
According to the published method (Stearn 1983), the morphological description of the new species was prepared from living plants and five dried herbarium specimens (HITBC: herbarium of Xishuangbanna Tropical Botanical Garden, the Chinese Academy of Science). Measurements were made using a vernier caliper. Herbarium and fresh specimens of Zingiber yunnanense (KUN: herbaria of Kunming Institute of Botany, the Chinese Academy of Science, Specimen number No.0833231 or No.0833232) and Zingiber teres (KUN, Specimen number No. 0833210) were also examined.
Etymology. The new species is named after Natma Taung National Park, Chin State, Myanmar, where it was discovered in a vast area of monsoon forest.
Phenology. Flowering from July to August. Distribution and habitat. Zingiber natmataungense is only known from the type locality. It is a terrestrial plant in monsoon forest dominated by Castanopsis tribuloides (Smith) A. de Candolle (Fagaceae) and Nyssa javanica (Blume) Wangerin (Nyssaceae) and narrowly distributed from 1900 m to 2000 m alt. It has been used as a traditional medicine by local Chin people, who cover wounds with freshly crushed rhizomes and also apply it as a substitution for common ginger to treat coughs by drinking water in which it has been boiled. Critical note. The new species most resembles Zingiber yunnanense and Z. teres. Detailed morphological differences between the two species are given in Table 1.