Actinostephanus (Gesneriaceae), a new genus and species from Guangdong, South China

Abstract

Actinostephanus, a new genus from southern China, is described and colorfully illustrated with a single species, A. enpingensis. This new genus is morphologically most similar to Boeica and Leptoboea, nevertheless, it can be easily distinguished from the latter two by the following characteristics, such as leaves in whorls of three, all closely clustered at the top; corolla bowl-shaped, 5-lobed, actinomorphic; capsule hard, oblong-ovoid, short, 3–4 mm long, densely appressed villous, wrapped by persistent densely pubescent calyx lobes, style persistent. The new genus and related genera were sequenced using the next-generation sequencing technique. The whole plastid genome of the new genus is 154, 315 – 154, 344 bp in length. We reconstructed phylogenetic trees using the dataset of 80 encoded protein genes of the whole plastid genome from 47 accessions based on ML and BI analyses. The result revealed that the new genus was recovering in a polytomy including Boeica, Rhynchotechum, and Leptoboea with strong support, congruent to the morphological evidence. A global conservation assessment was also performed and classifies A. enpingensis as Least Concern (LC). In addition, after a review of recently described species of Gesneriaceae, we propose that plant enthusiasts, especially Gesneriad fans, have been playing an increasingly important role in the process of new taxa-discoveries.

Plastome evolution and phylogenomics of Trichosporeae (Gesneriaceae) with its morphological characters appraisal

“…(2020) showed that Lysionotus was a sister group of Oreocharis based on whole plastomes (PP BI =0.68, BS ML =44%). However, Wen et al. (2022) showed that Lysionotus was close related to Primulina and Petrocodon based on 80 CDSs (PP BI =0.87, BS ML =88%).…”

Langbiangia, a new genus of Gesneriaceae endemic to Langbiang Plateau, southern Vietnam and a taxonomic endeavor to achieve key targets of the post-2020 global biodiversity framework

“…Given the biogeographical, ecological (Fig 2 ), morphological (Figs 3 and 4), and phylogenetic distinctness (Fig 5) of the Langbiang Primulina, our study clearly shows that the clade composed of these three species should be recognized as a distinct genus as those recently described genera of the subtribe Didymocarpinae [65,66,[86][87][88][89][90]. With the reduction of these three species, the total number of Primulina known from Vietnam decreases from 24 [58] to 21 species.…”

“…2,500 species [63]. In recent decades, recorded diversity in the subfamily has grown considerably as new taxa are being described continuously [e.g., 58,[64][65][66] especially in Vietnam [55][56][57][58][66][67][68][69][70][71]. However, molecular phylogenetic studies in the past decade also showed that traditional taxonomy of Gesneriaceae had utilized traits that are homoplasious [72][73][74][75][76].…”

“…More recently, Chirita umbrophila C.Y.Wu ex H.W.Li, a species with uncertain generic placement [ 75 ], was shown to be conspecific with Loxostigma kurzii (C.B.Clarke) B.L.Burtt [ 85 ]. On the other hand, phylogenetic studies of materials sampled from further botanical exploration also revealed lineages that are distinct and worthy of generic recognition (e.g., Actinostephanus F.Wen, Y.G.Wei & L.F.Fu [ 65 ], Billolivia D.J.Middleton [ 86 ], Chayamaritia D.J.Middleton & Mich.Möller [ 87 ], Glabrella Mich.Möller & W.H.Chen [ 88 ], Michaelmoelleria F.Wen, Y.G.Wei & T.V.Do [ 66 ], Middletonia C.Puglisi [ 89 ], Rachunia D.J.Middleton & C.Puglisi [ 90 ], etc.). These recent taxonomic changes and novelties of the didymocarpoid Gesneriaceae underscore the importance of incorporating molecular information in achieving a stable classification of Asian Gesneriaceae.…”

Another Recently Recognized Monotypic Genus Is No Longer Monotypic: A Second Species of Pachycaulos (Gesneriaceae) from the Huancabamba Depression in Northern Peru

“…It is remarkable that even since this publication, three monotypic genera of Gesneriaceae have been published in the Paleotropical subfamily Didymocarpoideae. Those new genera are Actinostephanus Y.G.Wei & L.F.Fu (Wen et al 2022), Bopopia Munzinger & J.R.Morel (Morel et al 2021), and Michaelmoelleria F.Wen, Y.G.Wei & T.V.Do (Wen et al 2020). A detailed overview of molecular phylogenetic studies with an emphasis of where sampling remains lacking was provided by Möller and Clark (2013).…”