Monotropa callistoma (Ericaceae), a new species based on morphological and molecular evidence from Hunan, China Author Wei, Ze State Key Laboratory of Plant Diversity and Specialty Crops, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China & National Botanical Garden, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China Author Liu, Li-Jia https://orcid.org/0009-0002-1392-8927 State Key Laboratory of Plant Diversity and Specialty Crops, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China & National Botanical Garden, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China & College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China Author Xuan, Jing Big Data and AI Biodiversity Conservation Research Center, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China & National Botanical Garden, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China Author Mo, Zhi-Qiong 0000-0002-0219-1213 Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China Author Ou Yang, Wen-Xiang Hunan Shunhuangshan National Nature Reserve Administration, Shaoyang 422700, Hunan, China Author Liu, Bing 0000-0002-6086-253X State Key Laboratory of Plant Diversity and Specialty Crops, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China & National Botanical Garden, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China & College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China Author Li, Min Big Data and AI Biodiversity Conservation Research Center, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China & National Botanical Garden, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China Author Wang, Qiang 0000-0002-0699-2034 State Key Laboratory of Plant Diversity and Specialty Crops, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China & National Botanical Garden, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China & College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China text PhytoKeys 2026 2026-02-27 271 145 160 journal article 314328 10.3897/phytokeys.271.177609 86d83e3d-f322-4688-a8c2-ed915031244f Monotropa callistoma Ze Wei, Li J. Liu & Bing Liu sp. nov. Figs 1 , 2 , 6 Diagnosis. Monotropa callistoma is characterised by its 4 or 5 glabrous petals (apically orange and basally white), 8–10 stamens with glabrous filaments, flowering period starting from March and nodding capsule at maturity. It is morphologically most similar to M. uniflora and Monotropastrum humile , but differs by the characters summarised in Table 2 . Type of Monotropa uniflora (Holotype PE 02432010). Type. China . • Hunan Province : Shaoyang City , Xinning County , Shunhuang Mountain , 1560 m elev., 29 March 2021 , Xuan Jing , Xie Gan , Wei Ze & Ouyang Wenxiang 60 ( holotype : PE [ PE 02432010 !]) (Fig. 5 ) Description. Herbs, fully mycoheterotrophic. Plants lacking chlorophyll, white when fresh, turning black upon drying. Stems erect, simple, unbranched, 9–15 cm tall, fleshy. Roots thick, densely branched, forming a bird’s-nest-like mass. Leaves scale-like, erect, alternate, oblong to broadly lanceolate, 12–18 mm long, 4–6.5 mm wide, apex obtuse, glabrous, margin nearly entire. Flower solitary, terminal, campanulate, 2–3 cm long, 1–1.5 cm in diameter. Sepals 4 or 5, scale-like. Petals 4 or 5, distinct, obovate-oblong, 2–2.5 cm long, 5–10 mm wide, fleshy, glabrous, orange in the apical one-quarter and white in the basal three-quarters, margin entire. Stamens 8–10; filaments glabrous; anthers yellow. Ovary glabrous, with parietal placentation, 1 - loculed; style 5–7 mm long; stigma expanded, funnel-shaped. Berries ellipsoid-globose, with the fruiting pedicel becoming curved and nodding at maturity. Monotropa callistoma sp. nov. A . Habitat and flowering plant; B . Flower, viewed from the top; C . Sepal; D . Petal; E . Stamen; F . Pistil; G . Berry; H . Transverse section of the berry fruit showing the parietal placentation; I . Mycorrhiza. Drawn by Yi F. Li. Phenology. Flowering from March to June; fruiting from April to July. Distribution and habitat. Currently known only from the type locality in Hunan Province, China . It grows in dense, humid broad-leaved forests at an elevation of around 1560 m , in association with ectomycorrhizal fungi. However, according to records from PPBC ( https://ppbc.iplant.cn/ ) and iNaturalist ( www. inaturalist. org / ), it has also been reported from Guizhou , Yunnan , Guangxi , Sichuan , Hunan , Xizang and Chongqing . As these records are based solely on photographs without supporting herbarium specimens, they are considered unverified and serve only as references. Vernacular name (Chinese name) . 美冠水晶兰 (měi guān shuǐ jīng lán). Etymology. The specific epithet callistoma is derived from the Greek calli - (beautiful) and - stoma (mouth), alluding to the aesthetically pleasing form and colouration of the corolla orifice. Preliminary conservation status. Data Deficient ( DD ). This species is currently known only from a single population. Further field surveys are needed to assess its full distribution and population size. The type locality is within a protected scenic area, which may offer some level of protection. Additional specimens examined ( Paratype ) . China . • Hunan Province : Shaoyang City , Xinning County , Shunhuang Mountain , 1560 m elev., 29 March 2021 , Xuan Jing , Xie Gan , Wei Ze & Ouyang Wenxiang 60 ( PE 024320009 !) .