﻿Melanoserispenghuana (Lactucinae, Cichorieae, Asteraceae), a new species from North-central Yunnan, China

﻿Abstract In this paper, we describe a new species, Melanoserispenghuana, from Mt. Jiaozi Xueshan located in North-central Yunnan, China. Despite its morphological similarities to M.likiangensis, M.penghuana exhibits distinct differences in leaf texture, shape of terminal lobes, indumentum of leaves, peduncles, and involucres, as well as the length of the achenes. Additionally, the conservation status of this species is classified as Vulnerable through data analysis from two field surveys.

During a field survey of Mt.Jiaozi Xueshan in 2021, we discovered a species of Melanoseris growing on the steep slopes on both sides of the Jiulonggou valley.It had large leaves, and the terminal lobes of leaves were extremely elongated, which caught our attention.Subsequent in-depth research confirmed that it may be an unpublished species of Melanoseris.To test the stability of its elongated terminal lobes, we conducted another field investigation in 2022 to examine its plant's morphological variation and population size.The results of the investigation showed that the unique terminal lobes were a stable characteristic within the population.Further morphological studies and analysis revealed both similarities and distinct differences between this plant and M. likiangensis (Franchet) N.Kilian & Ze H.Wang. Based on these findings, the authors reached the conclusion that this plant represents a newly identified species, which is comprehensively described and illustrated in this study.

Material and methods
To conduct the morphological description of the new species, we observed and photographed live plants in the field.Additionally, we utilized herbarium collections (KUN, GTZM) from these occasions.For morphological comparative analysis, we referred to the keys of the genus and descriptions of the species in Flora Reipublicae Popularis Sinicae (Shih 1997) and Flora of China (Shih and Kilian 2011).To facilitate further comparisons, we examined the protologue of M. likiangensis (Franchet 1895), as well as the specimen photographs in the herbaria IBSC, E, K, KUN, P, and PE.The morphology of trichomes and pappus, as well as the length of ligules, anther tubes, and achenes, were observed or measured using an anatomy microscope (OD500H) or a light microscope (Olympus DP72) on fresh or dried specimens.The classification of trichomes in this study followed Ramayya's classic treatment of trichomes on Compositae (Ramayya, 1962).Photographs were taken using a Canon EOS 77D and a Dell E2014Hf camera.Figures were edited, arranged, and merged using Adobe Illustrator CS4.Additionally, a distribution map was generated with QGIS 3.32.2.Diagnosis.Melanoseris penghuana is most similar to M. likiangensis, but differs from the latter primarily in the following characteristics: leaves thick papery (vs.papery), clearly hairy (vs.glabrous or sparsely hairy), terminal lobes of basal and lower leaves elongated triangular (vs.broad triangular), the length 3-4 times (vs.1-1.5 times) that of the width; peduncles covered with simple filiform hairs (vs.multiseriate capitate glandular hairs), involucres glabrous (vs.glandular hispid), achenes ca.9.5 mm (vs.ca.7 mm).
Phenology.Flowering and fruiting from September to October.Etymology.The specific epithet "penghuana" is named in honor of Professor Hua Peng, a renowned expert in plant taxonomy in China, for his outstanding contributions to the protection of Mt.Jiaozi Xueshan.
Conservation status.Melanoseris penghuana is found distributed along the steep grassy slopes on both sides of the Jiulonggou valley in Mt.Jiaozi Xueshan, Yunnan Province.In 2021 and 2022, the authors discovered three subpopula- tions; each of them had a considerable number of flowering plants and seedlings with only rosette leaves.Preliminary estimates suggest that there are more than 250 mature individuals.Although the current survey indicates that the distribution of M. penghuana is relatively concentrated, it is worth noting that its distribution areas are located within the Jiaozi Xueshan National Nature Reserve, where human disturbance is minimal.As a result, its habitat is relatively well protected.Thus, based on its very restricted population and the number of mature individuals estimated to be larger than 250 but fewer than 1000 (IUCN 2012(IUCN , 2022))

Discussion
Melanoseris likiangensis is an endemic species found in Northwest Yunnan, China (Fig. 3).Most of its specimens were collected several decades ago.Currently, there are still unresolved issues regarding the classification of M. likiangensis.For example, among the specimens defined as M. likiangensis, there are two types of inner involucral bracts: some have 5 bracts while others have 8 bracts.Furthermore, there is no consensus yet on whether M. bonatii (Beauverd) Ze H.Wang, a species found in Northeastern Yunnan, is conspecific with M. likiangensis.Resolving these taxonomical issues necessitates more specimen studies and specialized field investigations.To accurately compare the morphological characteristics of M. penghuana and M. likiangensis, we consulted the original description of M. likiangensis in the protologue (Franchet 1895).The main morphological differences between these two species are detailed in Table 1.The continuity of a new species' population often receives significant attention from taxonomists.In the case of Melanoseris penghuana, the expansion of its population is influenced by a combination of unfavorable and favorable factors.One of the unfavorable factors is the relatively low number of head inflorescences on each plant, and what's worse, there are only 10-12 florets per inflorescence.Furthermore, the author observed that the inflorescences of this species, similar to Sinoseris muliensis (Y.S.Chen, L.S.Xu & R.Ke) Ze H.Wang, N.Kilian & H.Peng (Wang et al. 2020) and M. kangdingensis Ze H.Wang (Zhong et al. 2023), are susceptible to parasitism by certain insects.These factors contribute to a lower quantity of seeds produced by M. penghuana plants.
On the other hand, there are several favorable factors contributing to the expansion of the Melanoseris penghuana population.Firstly, the species is distributed in the Jiaozi Xueshan National Nature Reserve, where the habitat is relatively well-protected.Secondly, the recent relocation of residents from Jiulonggou Village has reduced human disturbance in the area where M. penghuana grows.Thirdly, based on the field survey conducted by the authors in 2022, the population of M. penghuana is relatively large and not as endangered as many other recently discovered plants (Ma et al. 2019;Huang et al. 2020;Qiu et al. 2020;Nong et al. 2021).Lastly, compared with the recently published M. kangdingensis (Zhong et al. 2023), the growing environment of M. penghuana is also steep, but the soil layer of its habitat is relatively well-developed.Therefore, the probability of successful seed germination of M. penghuana after landing is much higher than that of M. kangdingensis.

Figure 1 .
Figure 1.Melanoseris penghuana sp.nov.A habitat B, C plants D root E trichomes on the peduncle under an anatomy microscope F trichomes on the peduncle under a light microscope (simple filiform hairs) G, H basal leaves I capitulum J involucre K achene L pappus.Photographed by Qin Tian.

Table 1 .
Comparison of the morphological characteristics between Melanoseris penghuana and M. likiangensis.