Deinostigma fasciculatum, a new species of Gesneriaceae in Yunnan, China

Abstract A new species of Deinostigma (Gesneriaceae) from Yunnan, China, Deinostigma fasciculatum W.H.Chen & Y.M.Shui, sp. nov., has been discovered and described. In the genus, the new species is similar to D. cicatricosum (W.T. Wang) D.J. Middleton & Mich. Möller and D. cyrtocarpum (D. Fang & L. Zeng) Mich. Möller & H.J. Atkins in dark purple flowers and falcate fruit, but differs from them mainly in the inflorescences with fasciculate flowers, calyx lobes (reflexed, narrowly lanceolate and 1.2–1.3 cm long), corolla tubes (sharply contracted below middle and white outside and below throat). The above three species grow nearby non-limestone wet cliffs and geographically isolated with different distributions (the new species in Southeast Yunnan, D. cicatricosum in Eastern Guangxi and D. cyrtocarpum in Southern Guangxi and Guangdong, China).

Previous orthography of species epithets in Deinostigma has used the feminine ending (i.e., D. "cycnostyla", see Möller et al. 2016). The generic name Deinostigma is neuter however, and so all epithets have been corrected here (e.g., to D. cycnostylum) to comply with Article 62.2(c) of the ICN.
After the surveys in the Sino-Vietnamese border (Fig. 1), a new species of Deinostigma from Jinping county, Yunnan province, China, has been confirmed and described.  (Wang et al. 1998;Wei et al. 2010;Möller et al. 2016;Wen et al. 2019). Although the above three Chinese species are similar to each other in habit and falcate fruit, the floral morphology and geographical distribution provide evidence to identify them respectively (Figs 1-3, Table 1).

Materials and method
We observed the morphology of the species and took photographs of the habitat and macro-morphological characters, both during the fieldwork in Jinping County, Southeastern Yunnan, China and at Kunming Botanical Garden. We also examined the specimens of Deinostigma in the herbaria (E, KUN, P & PE). All micro-morphological characters were observed and photographed with a Leica S8 APO stereomicroscope (Shanghai, China) and a Nikon D700 microscope camera (Tokyo, Japan).
Phenology. Flowering is from May to August and fruiting from July to September. Etymology. The name refers to the flowers, which are fasciculate on inflorescences of the new species.   Conservation state. The new species has been only observed from the type locality in the nature reserve, with ca. 30, 000 m 2 area (300 m × 100 m) and ca. 160 mature individuals on the cliff. The type locality is located in a deep valley with a small power station. Occasionally, local people go there to camp. Additionally, due to the building of a road, some of the slopes may become unstable and fall, resulting in some individuals being destroyed in the future. So, we hereby assessed the new species as "Critically Endangered (CR)" (C2+a+ii or B2+b+iii). (IUCN 2012(IUCN , 2017.
Note. Deinostigma cyrtocarpum is easily distinguished from D. cicatricosum and D. fasciculatum by its short calyx (Figs 1, 3J). Secondly, in D. cicatricosum and D. fasciculatum, corolla tubes are obviously contracted at the middle. As to the L/U ratio (width of lower part/width of upper part of corolla tube), the L/U ratio of D. cicatricosum is about 1/2.5 and lightly contracted, while the L/U ratio of D. fasciculatum is about 1/5 and sharply contracted (Figs 2, 3). Besides, after the careful examination of the type specimens, Deinostigma minutihamatum is distributed in Central Vietnam with 2300 m elevation and characterised by almost straight capsules instead of falcate capsules and so considerably different from the Chinese species of the genus with falcate capsules (Fig. 2B; Wang et al. 1998, Wei et al. 2010.