Monotropa callistoma (Ericaceae), a new species based on morphological and molecular evidence from Hunan, China Wei, Ze Liu, Li-Jia Xuan, Jing Mo, Zhi-Qiong Ou Yang, Wen-Xiang Liu, Bing Li, Min Wang, Qiang PhytoKeys 2026 2026-02-27 271 145 160 Ze Wei, Li J. Liu & Bing Liu Ze Wei, Li J. Liu & Bing Liu 2026 Magnoliopsida Ericaceae Monotropa Plantae Ericales Tracheophyta species callistoma sp. nov.   Figs 1, 2, 6   Diagnosis.   Monotropa callistomais 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. unifloraand  Monotropastrum humile, but differs by the characters summarised in Table 2.   Figure 5. Type of  Monotropa uniflora(Holotype PE 02432010).   Type.   China. • Hunan Province: Shaoyang City, Xinning County, Shunhuang Mountain,  1560 melev.,  29 March 2021,  Xuan Jing, Xie Gan, Wei Ze& Ouyang Wenxiang60( 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 cmtall, fleshy. Roots thick, densely branched, forming a bird’s-nest-like mass. Leaves scale-like, erect, alternate, oblong to broadly lanceolate, 12–18 mmlong, 4–6.5 mmwide, apex obtuse, glabrous, margin nearly entire. Flower solitary, terminal, campanulate, 2–3 cmlong, 1–1.5 cmin diameter. Sepals 4 or 5, scale-like. Petals 4 or 5, distinct, obovate-oblong, 2–2.5 cmlong, 5–10 mmwide, 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 mmlong; stigma expanded, funnel-shaped. Berries ellipsoid-globose, with the fruiting pedicel becoming curved and nodding at maturity.   Figure 6.   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, Xizangand 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 callistomais 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 melev.,  29 March 2021, Xuan Jing, Xie Gan, Wei Ze& Ouyang Wenxiang60 ( PE 024320009!). 6161064301 2021-03-29 PE Xuan Jing & Xie Gan & Wei Ze & Ouyang Wenxiang China Xinning County 1560 Shunhuang Mountain Shaoyang City PE 02432010 1 Hunan Province holotype 6161064302 2021-03-29 PE Xuan Jing & Xie Gan & Wei Ze & Ouyang Wenxiang China Xinning County 1560 Shunhuang Mountain Shaoyang City PE 024320009 1 Hunan Province paratype