Yeonchan Kang1P, Yujin Jeon1, Young-Kee Kim1, Heewon Ji1,

Bo-Mi Nam2, and Jun-Ho Song1

1Department of Biology, Chungbuk National University, Cheongju, Korea;

2Division of Botany, Honam National Institute of Biological Resources, Mokpo, Korea

The genus Arisaema Mart. (Araceae Juss.) comprises approximately 180 species distributed worldwide across tropical and temperate regions. In Korea, six species and one subspecies are recognized. Arisaema thunbergii Blume subsp. geomundoense S.C.Ko is an endemic Korean subspecies, traditionally distinguished by the color and wrinkled texture of its spadix appendage. However, a recent study of chloroplast genome of the genus Arisaema suggested that A. thunbergii subsp. geomundoense should be treated as a synonym of A. thunbergii subsp. thunbergii. The present study aimed to provide a detailed description and taxonomic assessment of A. thunbergii subsp. geomundoense based on micromorphological observations and comparative sequence analyses. Leaf cuticular micromorphology and palynology revealed no significant differences between A. thunbergii subsp. geomundoense and A. thunbergii subsp. thunbergii. In addition, we detected that no single-nucleotide polymorphism (SNP) regions were in the internal transcribed spacer (ITS) sequences between the two taxa. These findings support previous plastome-based results and confirm that A. thunbergii subsp. geomundoense should be regarded as synonym of A. thunbergii subsp. thunbergii. Nevertheless, some studies have proposed that A. thunbergii subsp. geomundoense is instead synonymous with A. thunbergii subsp. urashima (H.Hara) H.Ohashi & J.Murata, an endemic subspecies of Japan. Further comprehensive studies on the A. thunbergii complex are therefore necessary to resolve clarify taxonomic boundaries and achieve a robust taxonomic revision of the genus Arisaema.

* This work was supported by a grant from the Honam National Institute of Biological Resources (HNIBR), funded by the Ministry of Climate, Energy and Environment (MCEE) of the Republic of Korea (Grant No. HNIBR202101107).