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There are more than 2035 Begonia species (Begoniaceae) reported currently in the world. Begonia arachnoidea was found as a new species within a small area in Southern China. In this study, we are reporting for the first time its chloroplast genome for the purpose to compare with the chloroplast genomic data from other plant taxa which were closely related to this new species. Our results show that the circular chloroplast genome of B. arachnoidea is 169,725 bp in length, with 35.49% GC content. The whole structure of the genome has 76,431 bp in a large single-copy (LSC) region, 18,146 bp in a small single-copy (SSC) region, and the two inverted repeat (IRs) regions are both 37,574 bp. There are 90 protein-coding genes, 8 rRNA genes, and 42 tRNA genes encoded in this genome. Final phylogenetic analysis revealed that B. arachnoidea is genetically closest to B. pulchrifolia and B. coptidifolia .

Begonia L. (Begoniaceae) is the sixth largest genus in the world which consists of more than 2,039 species. Many species of Begonia have highly ornamental leaves and flowers, so they are mainly used for ornamental purposes, and some species can also be used as medicines or vegetables. Begonia gulongshanensis is a newly discovered species in 2018 which occurs exclusively in Jingxi county in Southern China, however, there are few studies on the molecular biology and phylogeny of this species currently. Therefore, we report its complete chloroplast genome sequence for the first time, hoping to provide a foundation for its future phylogenetic analysis. The chloroplast genome of B. gulongshanensis was 169,153 bp in size, which contained a large single-copy region of 75,998 bp, a small single-copy region of 18,063 bp, and two inverted repeat regions of the same 37,546 bp. The total GC content was 35.51%. The genome encodes 42 transfer RNA genes, 8 ribosomal RNA genes and 90 protein-coding genes. The phylogenetic analysis indicated that the genetic relationship between B. gulongshanensis and the other three begonias was very close, but there was still certain distance.

Both Impatiens macrovexilla and I . macrovexilla var. yaoshanensis have potential to be exploited as ornamental plants, despite some of their morphological differences. In the present study, the complete chloroplast genome sequences of the two taxa are reported for the first time, which could facilitate their infraspecies classification, and analyses of their evolution, phylogeny, and breeding potential. The chloroplast genomes of I . macrovexilla and I . macrovexilla var. yaoshanensis were 152,437 and 152,286 bp in size, respectively. Their total GC contents were 36.77 and 36.80%, respectively. Both genomes contained 88 protein-coding genes, 8 rRNA genes, and 37 tRNA genes. The phylogenetic analysis revealed that the two specimens clustered next to each other and were closely related to I . alpicola , I . fanjingshanica , and I . piufanensis , but relatively distant from I . guizhouensis and I . pritzelii .