Petrocodon subpalmatinervis (W.T.Wang) F.Wen & Z.L.Li, 2023

Li, Zheng-Long, Huang, Zhang-Jie, Chen, Da-Wei, Hong, Xin & Wen, Fang, 2023, A new combination and a new synonym of Gesneriaceae in China, PhytoKeys 232, pp. 99-107 : 99

Petrocodon subpalmatinervis (W.T.Wang) F.Wen & Z.L.Li comb. nov.

Didymocarpus subpalmatinervis W.T.Wang, Novon 7(4): 428-429. 1997. Type: China. Yunnan: Y-dje, near Lou-lan, July 1905, Fr. Ducloux 3711 (P: holotype P04060419!; isotypes P04060165!, P04060418!). Basionym.

Petrocodon lithophilus = Petrocodon lithophilus Y.M.Shui, W.H.Chen & Mich. Möller, Sys. Bot. 39(1): 325. 2014. syn. nov. Type: China. Yunnan: Shilin County, Naigu Stone Forest, alt. 1848 m, on rocks on cliffs, 29 August 2012, Y.M. Shui et al. B2012-078 (KUN: holotype KUN-1519980!; isotype KUN-1519978!).

Chinese Vernacular name.

掌脉石山苣苔 (Zhǎng Mài Shí Shān Jù Tái).

Distribution and habitat.

This species is endemic to Shilin County, Yunnan Province, China, growing in narrow cracks on rocks. Accompanying plants include other shade herbs and trees.

Proposed IUCN conservation status.

Naigu Stone Forest is a famous scenic spot for many tourists. The population of Petrocodon subpalmatinervis is easily affected by human activities. For example, tourists probably collect the conspicuous flowers of P. subpalmatinervis while they visit the scenic spot and walk along the trails among the Karst peaks and hills of Naigu Shilin. As mature individuals are easily damaged, the population will likely gradually decline year by year. According to the results of our field investigation in the type locality and adjacent regions, the EOO and AOO of P. subpalmatinervis are about 800 km2 and 30 km2. Despite the severe drought in the second half of 2022 seriously influencing the plant population, there is still a high number of individuals (more than 5 000) surviving in the scenic spot. In addition, authors also found several small populations (total>1 000) in the Karst landscape surrounding the type locality, Naigu Shilin. Following the IUCN Red List Categories and Criteria ( IUCN 2022), this species is evaluated as Endangered [EN B1ab (i, ii, iii, iv)+2ab (i, ii, iii, iv)].

Notes.

When Wang published the protologue of Didymocarpus subpalmatinervis , the collection date read 1909. But, on the website of CVH and the herbarium P, the collection date of the information of the specimen we consulted was 1905. Their two different collection years are confusing. We carefully compared the labels of three type specimens of D. subpalmatinervis with the collection number ' 3711 ' and found that the collector’s writing habits might have caused this misunderstanding. Ducloux’s personal collection number increased with time like many collectors. For example, the collection number of Berberis bodinieri H. Lév. he collected in 1896 was ' 0004 '; in 1904, the collection number of Potamogeton distinctus A. Benn. was ' 2571 '; in 1905, he collected Cornus capitata Wall. at the same place (Y-dje near Lou-lan) with the collection number ' 3715 '; In 1909, the collection number of Merremia yunnanensis (Courchet & Gagnep.) R.C.Fang has reached ' 6398 '. Therefore, it seems likely that the specimens of D. subpalmatinervis with the collection number Fr. Ducloux 3711 were collected in 1905.

For some species published decades or even a hundred years ago, obtaining molecular materials for systematic analysis is challenging because there may be only one type specimen or a few specimens, or they are stored in a foreign herbarium ( Wei 2018; Kong et al. 2021). Despite this complicated background, it is still reasonable and accurate to conduct an analysis and verification of the type specimen of the dubious species. When combined with the collecting history of the Ducloux, and the current situation of the existing population ( Wei et al. 2022), we are confident about the name and status.