Monotropa callistoma (Ericaceae), a new species based on morphological and molecular evidence from Hunan, China

Abstract

Figures

Habitat and flowering habit of Monotropa callistoma. Photographed by Ze Wei.

Morphology of Monotropa callistoma. A. Flower; B. Flowering plant showing scale-like leaves; C. Petals; D. Stamens; E. Transverse section of the ovary; F, G. Baccate fruit (berry) and its transverse section showing the parietal placentation; H. Mycorrhiza. B–E. Photographed by Zi Wang and others photographed by Ze Wei.

Majority-rule consensus tree from Bayesian Inference (BI), based on 49 nrITS sequences. Bayesian posterior probabilities (PP) and Maximum Likelihood (ML) bootstrap values (BS) are shown above the branches, respectively. New species are highlighted in bold, while other newly-sequenced sequences are marked with an asterisk (*).

Majority-rule consensus tree from Bayesian Inference (BI), based on 23 single-copy coding sequences (CDSs) extracted from 24 chloroplast (cp) genomes. Bayesian posterior probabilities (PP) and Maximum Likelihood (ML) bootstrap values (BS) are shown above the branches, respectively. New species are highlighted in bold, while other newly-sequenced sequences are marked with an asterisk (*).

Type of Monotropa callistoma (Holotype PE02432010).

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.

Tables

Table 1.. Distribution of existing tribes, genera and species within Subfamily Monotropoideae. Species occurring in East Asia are highlighted in bold; those included in this study are marked with an asterisk (*).

Tribe	Genus		Species		Distribution
Tr. Pterosporeae Baill. (1891)	1	Pterospora Nutt.	1	Pterospora andromedea Nutt. *	Alaska to Mexico
	2	Sarcodes Torr.	1	Sarcodes sanguinea Torr. *	W. U.S.A. to NW. Mexico
Tr. Monotropeae Dumort. (1829)	3	Pleuricospora A.Gray	1	Pleuricospora fimbriolata A.Gray *	W. Canada to W. U.S.A.
	4	Monotropastrum Andres	2	Monotropastrum humile (D.Don) H.Hara *	Himalaya to Russian Far East and Temp. E. Asia, Indo-China, N. Sumatera
				Monotropastrum kirishimense Suetsugu	Japan (Honshu, Kyushu)
	5	Eremotropa Andres	1	Eremotropa sciaphila Andres *	S. Central China
	6	Monotropsis Schwein. ex Elliott	2	Monotropsis odorata Schwein. *	SE. U.S.A
				Monotropsis reynoldsiae (A.Gray) A.Heller	N. & Central Florida
	7	Allotropa Torr. & A.Gray	1	Allotropa virgata Torr. & A.Gray *	W. Canada to W. U.S.A
	8	Hemitomes A.Gray	1	Hemitomes congestum A.Gray *	W. Canada to W. U.S.A
	9	Pityopus Small	1	Pityopus californicus (Eastw.) H.F.Copel. *	Washington to California
	10	Monotropa L.	3	Monotropa brittonii Small	SE. North Carolina to Florida
				Monotropa coccinea Zucc.	Mexico to Colombia
				Monotropa uniflora L. *	N. Pakistan to Russian Far East and Japan, Canada to Mexico
	11	Hypopitys Hill	1	Hypopitys monotropa Crantz *	Temp. Northern Hemisphere to Central America
	12	Cheilotheca Hook.f.	4	Cheilotheca crocea L.Wu & Yan Liu	China (Guangxi)
				Cheilotheca khasiana Benth. & Hook.f.	Assam (Meghalaya)
				Cheilotheca malayana Scort. ex Hook.f.	Peninsula Malaysia (Perak)
				Cheilotheca sleumerana H.Keng	Sumatera

Table 2.. Morphological comparison between Monotropa uniflora, Monotropastrum humile and Monotropa callistoma sp. nov.

Character	Monotropa uniflora	Monotropa callistoma	Monotropastrum humile
Petals	5–6, distinct, cuneate or obovate-oblong, 1.2–1.6 cm long, 5.5–7 mm wide at the broadest apex, margin irregularly toothed, inner surface often densely villous, caducous.	4–5, distinct, obovate-oblong, 2–2.5 cm long, 5–10 mm wide, fleshy, glabrous, margin entire, apical one-quarter orange and basal three-quarters white.	3–5, usually oblong, 10–20 × 5–15 mm, slightly longer than sepals, abaxially glabrous, adaxially pubescent, base broadly saccate.
Stamen number	10–12	8–10	8–12
Filaments	Pubescent	Glabrous	Pubescent
Style	2–3 mm long; stigma funnel-shaped.	5–7 mm long; stigma funnel-shaped.	2–5 mm long; stigma funnel-shaped, often lead grey-blue and sparsely long-hairy.
Fruit	Capsule, erect at maturity.	Baccate fruit (berry), pedicel curved and nodding at maturity.	Berries erect to nodding, white, ovoid-globose.
Flowering period	June–October	March–June	April–August
Fruiting period	September–November	April–July	May–September

Table 3.. Features of seven newly sequenced Monotropoideae plastomes.

Taxa	Voucher Specimen	Total length (bp)	GC content (%)	Gene numbers
Monotropa uniflora L.	PE00058751	42,959	28.5	47
Monotropa callistoma sp. nov.	PE02432009 (Paratype)	41,085	30.8	44
Monotropa callistoma sp. nov.	PE02432010 (Holotype)	41,041	30.8	44
Hypopitys monotropa Crantz	PE00058638	34,955	34	35
Monotropastrum humile (D. Don) H. Hara	PE01180237	40,507	30.6	43
Pterospora andromedea Nuttall	PE (Accession number pending, Sheet number 36238)	48,957	33.4	38
Pterospora andromedea Nuttall	PE (Accession number pending, Sheet number 1281043)	49,007	33.3	38

1	Berry, pendulous at maturity; sepals persistent	2
–	Capsule, erect at maturity; sepals deciduous	4
2	Filaments, style and petals glabrous; flower apex orange	Monotropa callistoma
–	Filaments, style and inner surface of petals pubescent; flowers white or pink	3
3	Tepals white; sepals (2–)3–5, oblong, spreading at anthesis	Monotropastrum humile
–	Tepals rosy pink; sepals 4–11, elliptic, constantly appressed to the petals throughout anthesis	Monotropastrum kirishimense
4	Plant entirely glabrous, bright red	Monotropa coccinea
–	Filaments and inner surface of petals densely pubescent; flowers greenish-yellow, ochroleucous or white	5
5	Sepals and petals not ciliate at margins; capsule 0.5–1.2(–1.4) cm long	Monotropa uniflora
–	Sepals and petals ciliate at margins, shallowly saccate at base; capsule larger, 1.5–2 cm long	Monotropa brittonii

Full text

Introduction

The subfamily Monotropoideae represents a unique lineage within the Ericaceae, being the only mycoheterotrophic and non-photosynthetic group amongst its nine subfamilies (Kron 1996; Kron et al. 2002; Liu et al. 2014). Members of this subfamily share a predominantly herbaceous habit, reduced embryos and a fully mycoheterotrophic and non-photosynthetic lifestyle, which has led to pronounced morphological reduction (Kron et al. 2002) and extensive loss of chloroplast genes (Logacheva et al. 2016; Braukmann et al. 2017; Liu et al. 2020). The subfamily currently comprises two tribes and twelve genera (Rose and Freudenstein 2014; Liu et al. 2017; Zhao et al. 2018; Freudenstein and Broe 2024). In recent years, several new species have been discovered in East Asia (Wu et al. 2016; Suetsugu et al. 2023), suggesting that its diversity may be underestimated. As of 2025, 19 species have been formally recognised (POWO 2025).

During a field survey in Xinning County, Hunan Province in March 2021, we encountered an unusual Monotropa population. Subsequent investigations from 2022 to 2025 included repeated observations of several populations across the Province. A thorough review of herbarium records and literature confirmed that its morphology is distinct from all three known species in the genus. Amongst these three species, Monotropa brittonii Small and Monotropa coccinea Zucc. are distributed only in the Americas, while Monotropa uniflora L. is widely distributed in East Asia and North America (Table 1). Although M. uniflora is morphologically most similar to the present species, significant differences exist in petal colour, indumentum, number of petals, number of stamens, filament pubescence, style length and fruit type. Similarly, Monotropastrum humile (D.Don) H.Hara, also widespread in East Asia, shows morphological affinities, but differs in petal colour, indumentum and style length. Phylogenetic analyses, based on nrITS and complete chloroplast genome sequences, strongly support its taxonomic distinction. Integrating morphological, phylogenetic and phenological evidence, we here recognise it as a new species of Monotropa (Ericaceae).

Methods and materials

Taxon sampling and data collection

Our sampling encompassed 11 of the 12 recognised genera within subfamily Monotropoideae, with the exception of Cheilotheca Hook.f. Arbutus unedo L. and Vaccinium macrocarpon Aiton were selected as outgroups, based on prior research (Braukmann et al. 2017; Rose et al. 2018; Freudenstein and Broe 2024). Forty-three nuclear ribosomal internal transcribed spacer (nrITS) region and 17 chloroplast (cp) whole genomes were downloaded from NCBI and six nrITS and seven chloroplast whole genomes were newly sequenced (Sarcodes Torr. and Pleuricospora A.Gray only have nr dataset, no cp dataset). Two samples of Monotropa callistoma were derived from the type (PE02432010) and other (PE02432009) specimens collected during our fieldwork. In addition, we newly sequenced five accessions of the tribe Monotropeae from the PE Herbarium, including Monotropa uniflora L. (1 sample, China), Monotropastrum humile (D. Don) H. Hara (1 sample, Japan), Hypopitys monotropa Crantz (1 sample, China) and Pterospora andromedea Nuttall (2 samples, USA). Detailed collection information for all samples is provided in Suppl. material 1: table SS1.

DNA extraction, amplification and sequencing

Total genomic DNA was extracted from approximately 20–30 mg of silica-gel-dried plant material using the standard CTAB (cetyl trimethylammonium bromide) method (Doyle et al. 1987). The quality-checked DNA samples were randomly sheared using a Covaris ultrasonicator to construct sequencing libraries. The library preparation workflow included end repair, A-tailing, adapter ligation, purification and PCR amplification. The constructed libraries were initially quantified using Qubit 2.0 and the insert size was checked with an Agilent 2100 Bioanalyzer. Libraries with the expected insert size were then accurately quantified using quantitative PCR (Q-PCR) to ensure quality. Qualified libraries were pooled in appropriate proportions, based on effective concentration and the desired data volume, followed by cluster generation on the cBOT system. Sequencing was performed on the Illumina NovaSeq 6000 platform to generate 5–8 Gb of raw data per sample.

The raw reads were processed with fastp (Chen et al. 2018) to remove adapters and low-quality sequences, yielding clean data for subsequent assembly (see Suppl. material 1: table SS2 for sequencing statistics). The nrITS region (ITS1-5.8S–ITS2-26S) and the complete chloroplast genome were assembled from the clean data using GetOrganelle v.1.7.1a (Jin et al. 2020). The assembled chloroplast genome was annotated using the Plastid Genome Annotator (PGA) (Qu et al. 2019) with the reference of Monotropa uniflora (NC_035582). The annotation was subsequently imported into Geneious v.2023.0.4 (Kearse et al. 2012) for manual verification and refinement. All sequence data utilised in our analyses are readily accessible in GenBank (Suppl. material 1: table SS1).

Phylogenetic analyses

Phylogenetic relationships were reconstructed using two datasets: the nuclear ribosomal internal transcribed spacer (nrITS) region (49 sequences) and 23 single-copy coding sequences (CDSs) extracted from 24 chloroplast (cp) genomes.

The nrITS sequences and 23 cp-CDS were aligned separately using MAFFT v.7.221 (Katoh and Standley 2013). The alignments were manually inspected in MEGA7 (Kumar et al. 2016) and subsequently refined using trimAl (Capella-Gutiérrez et al. 2009). The best-fit nucleotide substitution models, selected under the Akaike Information Criterion (AIC) by MrModelTest v.2.4 (Posada and Crandall 1998), were GTR+G for the nrITS dataset and GTR+I+G for the cp dataset.

Maximum Likelihood (ML) analyses were conducted with RAxML v.8.2.12 (Stamatakis 2014), with branch support assessed from 1000 bootstrap replicates. Bayesian Inference (BI) was performed using MrBayes v.3.2.7 (Ronquist et al. 2012), running two independent Markov Chain Monte Carlo (MCMC) analyses for one million generations each, with trees sampled every 1000 generations. The first 25% of sampled trees were discarded as burn-in. The consensus phylogenetic trees were visualised in FigTree v.1.4.4(available at: http://tree.bio.ed.ac.uk/software/figtree/).

Results

Morphological comparisons

This new species (Figs 1, 2) differs from its congener, Monotropa uniflora, by its petals (4 or 5, glabrous, apically one-quarter orange and basally three-quarters white vs. 5 or 6, white and typically densely villous on the inner surface in M. uniflora), stamens (8–10 with glabrous filaments vs. commonly 10 with pubescent filaments), earlier flowering period (starting from March vs. starting from June) and baccate fruit with parietal placentation, 1-loculed (vs. capsular fruit with axile placentation, 5-loculed). This species is also quite similar to Monotropastrum humile (D.Don) H.Hara, but can similarly be distinguished by corolla colour, pubescence and stamen length. A detailed morphological comparison is presented in Table 2 and the key to the species of Monotropa s.s. and Monotropastrum.

Habitat and flowering habit of Monotropa callistoma. Photographed by Ze Wei.

Morphology of Monotropa callistoma. A. Flower; B. Flowering plant showing scale-like leaves; C. Petals; D. Stamens; E. Transverse section of the ovary; F, G. Baccate fruit (berry) and its transverse section showing the parietal placentation; H. Mycorrhiza. B–E. Photographed by Zi Wang and others photographed by Ze Wei.

Table 2.: Morphological comparison between Monotropa uniflora, Monotropastrum humile and Monotropa callistoma sp. nov.

Chloroplast genome features of Monotropa

callistoma and related species

Our results demonstrate a pronounced reduction in chloroplast genome size and gene content across the non-photosynthetic subfamily Monotropoideae (Table 3). The seven newly-sequenced chloroplast genomes ranged from ~ 34 kbp (Hypopitys monotropa) to ~ 49 kbp (Pterospora andromedea) and encoded 35 genes (Hypopitys monotropa) to 47 genes (Monotropa uniflora). The chloroplast genome of the new species, Monotropa callistoma, was assembled to a length of 41,041–41,085 bp and was annotated with 44 genes. It lacks several typical chloroplast genes, including trnM-CAT (and its copy) as well as trnF-GAA, reflecting the ongoing gene loss associated with the transition to a heterotrophic lifestyle in this lineage.

Phylogenetic analyses

Both phylogenetic reconstructions (Figs 3, 4) strongly supported Monotropa callistoma as a monophyletic lineage (PP = 1.00, BS = 100 in both datasets), which was placed within the genus Monotropa and resolved as sister to its type species, M. uniflora, with high support (PP = 1.00, BS = 100 in the plastome tree; PP = 1.00, BS = 98 in the nrITS tree).

Majority-rule consensus tree from Bayesian Inference (BI), based on 49 nrITS sequences. Bayesian posterior probabilities (PP) and Maximum Likelihood (ML) bootstrap values (BS) are shown above the branches, respectively. New species are highlighted in bold, while other newly-sequenced sequences are marked with an asterisk ().*

Majority-rule consensus tree from Bayesian Inference (BI), based on 23 single-copy coding sequences (CDSs) extracted from 24 chloroplast (cp) genomes. Bayesian posterior probabilities (PP) and Maximum Likelihood (ML) bootstrap values (BS) are shown above the branches, respectively. New species are highlighted in bold, while other newly-sequenced sequences are marked with an asterisk ().*

In the nrITS phylogeny (Fig. 3), all eleven sampled genera formed well-supported monophyletic groups. This result corroborates previous taxonomic proposals to resurrect Eremotropa (Zhao et al. 2018) and retain Hypopitys (Liu et al. 2017; Freudenstein and Broe 2024). The tribe Monotropeae was divided into three major clades. Within the clade containing Monotropa, the genus was most closely related to Monotropastrum, followed successively by Eremotropa and Monotropsis. This intergeneric relationship was also supported by the chloroplast phylogeny (Fig. 4).

Discussion

Our integrative study, combining morphological observation, phylogenetic analysis and phenological investigation, provides evidence for the recognition of Monotropa callistoma as a new species. This discovery not only enriches the biodiversity of the genus Monotropa, but also offers fresh insights into the evolutionary dynamics and species delimitation within the enigmatic subfamily Monotropoideae.

The distinct morphological characters of M. callistoma provide the most direct evidence for its taxonomic distinction. The combination of 4–5 glabrous, bicoloured (apically orange and basally white) petals, 8–10 stamens with glabrous filaments and a nodding berry fruit at maturity is not found in any of the three previously known Monotropa species and two Monotropastrum species (Linnaeus 1753; Zuccarini 1832; Small 1927; Fang and Hu 1990; Luteyn et al. 1995; Klooster and Culley 2009; Suetsugu et al. 2023). Particularly, the petal colouration is a remarkable and previously unreported trait in these two genera. This suite of morphological differences is further solidified by a clear phenological barrier. The flowering period of M. callistoma (March–June) exhibits minimal overlap with that of its sister species, M. uniflora (June–October). This phenological isolation represents a potent pre-zygotic reproductive barrier, effectively preventing gene flow and facilitating independent evolutionary trajectories (Coyne and Orr 2004; Wang et al. 2021).

The baccate fruit of M. callistoma, however, prompts a deeper consideration of its generic placement. Unilocular ovaries, parietal placentation and baccate fruits are considered key characteristics distinguishing Monotropastrum from Monotropa, which typically bears capsules (Wallace 1987; Stevens et al. 2004; Qin and Wallace 2005; Tsukaya et al. 2008; Zhao et al. 2018). In this respect, M. callistoma aligns more closely with the definition of Monotropastrum. Nonetheless, incorporating M. callistoma into Monotropastrum would conflict with the current circumscription of the genus and its phylogenetic position, likely rendering Monotropastrum paraphyletic. Multiple evolutionary transitions from dry to fleshy fruits have occurred throughout angiosperm history, including at least 58 independent shifts from capsules to berries (Xiang et al. 2024). This suggests that fruit type may be a relatively labile trait. Additional characters, such as anther dehiscence patterns, have also been noted to differ between the genera (Hara 1966). Given the limited morphological research on many species within this group, generic boundaries remain somewhat ambiguous.

Considering the above and in light of the current incomplete sampling and morphological characterisation across the lineage, we adopt a conservative and practical taxonomic approach. We tentatively place this new species within a broader (sensu lato) concept of the genus Monotropa and provisionally include Monotropastrum humile within this framework as well. We refrain from making formal nomenclatural recombinations at this time, pending future studies with expanded sampling and more comprehensive investigations of morphological and functional traits to definitively resolve the taxonomic relationships amongst these closely-related groups.

The robust support from both chloroplast genome and nrITS phylogenies confirms the genetic distinctness of M. callistoma (Figs 3, 4). Its consistent position as a well-supported monophyletic lineage sister to M. uniflora validates the morphological observations and confirms its placement within the genus Monotropa. Furthermore, our phylogenetic reconstructions corroborate recent taxonomic revisions concerning the monophyly of genera within Monotropoideae (Liu et al. 2017; Zhao et al. 2018; Freudenstein and Broe 2024). The clear resolution of the Monotropa-Monotropastrum-Eremotropa-Monotropsis clade provides a solid framework for understanding generic relationships within the tribe.

The highly reduced chloroplast genomes assembled in this study, including that of M. callistoma, are emblematic of the extreme evolutionary consequences of a fully mycoheterotrophic lifestyle. The extensive gene loss and size reduction observed (Table 3) align with the pattern widely documented in other non-photosynthetic plants (Lallemand et al. 2016; Logacheva et al. 2016; Braukmann et al. 2017; Liu et al. 2020; Suetsugu et al. 2024; Harada et al. 2025). This reductive evolution is driven by the relaxation of functional constraints on the photosynthetic apparatus and the translational machinery in the absence of light (Wicke and Naumann 2018). The persistence of a minimal plastome in M. callistoma and its relatives suggests that certain genes, likely those involved in essential non-photosynthetic functions, such as gene expression and possibly interactions with the mycorrhizal symbiont, are under purifying selection and are retained.

The discovery of M. callistoma in a well-botanised region of subtropical China underscores that the diversity of mycoheterotrophic plants may still be underestimated. Their cryptic nature, small size and ephemeral appearance above ground make them easily overlooked. Moreover, species complexes that are morphologically similar, but reproductively isolated by phenology or other subtle characters may be lumped under a single name (Rose and Freudenstein 2014; Freudenstein et al. 2016).

Conclusions

In conclusion, we describe Monotropa callistoma as a new species, based on a synthesis of multiple lines of evidence. This study demonstrates how the interplay of morphological specialisation, phenological shifts and genetic divergence can drive speciation even in lineages with highly reduced body plans. It also reinforces the notion that continued exploration and application of molecular tools are crucial for accurately documenting the true extent of plant diversity, particularly for inconspicuous and functionally specialised groups.

Taxonomic treatment

Monotropa

callistoma

Taxon classificationPlantaeEricalesEricaceae

Ze Wei, Li J.Liu & Bing Liu sp. nov.

82443CA4-9E4F-5D85-98E3-236F00EC1C75

urn:lsid:ipni.org:names:77371852-1

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 callistoma (Holotype PE02432010).

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 [PE02432010!]) (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

(Isotype). China. • Hunan Province: Shaoyang City, Xinning County, Shunhuang Mountain, 1560 m elev., 29 March 2021, Xuan Jing, Xie Gan, Wei Ze & Ouyang Wenxiang 60 (PE02432009!).

Key to the species of Monotropa s.l. (Monotropa s.s. & Monotropastrum)

**: **

Supplementary Material

XML Treatment for Monotropa callistoma