• Korean Journal of Plant Taxonomy
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• v.52 no.2
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• pp.85-96
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• 2022

The plant "Hong-do-go-deul-ppae-gi" has been considered as Crepidiastrum × muratagenii, a hybrid between C. denticulatum and C. lanceolatum, based on its morphological traits and geographical distribution. To reveal the hybrid origin of Hong-do-go-deul-ppae-gi, we examined additional morphological traits of this plant and its putative parents (C. denticulatum, C. lanceolatum, C. platyphyllum) and analyzed one nuclear ribosomal internal transcribed spacer (ITS) region and four chloroplast regions (trnT-L, trnL-F, rpl16 intron, and rps16 intron). As a result of examining the morphological traits, putative hybrid individuals were classified into three types based on the habit, cauline leaf, outer phyllary, and achene beak traits. A molecular analysis found that the ITS sequences of Type 1 and Type 2 individuals showed additive species-specific sites of C. denticulatum and C. lanceolatum. Plastid sequences of Type 1 and Type 2 individuals showed C. denticulatum and C. lanceolatum sequences, respectively. However, Type 3 individuals had ITS and plastid sequences corresponding to C. denticulatum. Accordingly, Type 1 and Type 2 individuals not only share morphological traits with C. denticulatum and C. lanceolatum but also show additive species-specific sites for C. denticulatum and C. lanceolatum, and not C. platyphyllum, supporting its origin as a hybrid between C. denticulatum and C. lanceolatum. Type 3 had morphological traits similar to other hybrid types but was distinguished with respect to outer phyllaries and demonstrated some resemblance to C. denticulatum. In a molecular analysis, Type 3 was found to be identical with regard to the sequence of C. denticulatum and was judged to be an ecological variation of C. denticulatum.

• Korean Journal of Plant Taxonomy
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• v.51 no.3
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• pp.198-204
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• 2021

The plant known as "Hong-do-go-deul-ppae-gi" on Hongdo Island, belonging to the genus Crepidiastrum, has been recorded as C. ×nakaii, a hybrid between C. denticulatum and C. platyphyllum. During a survey of the flora of Hongdo Island, we reexamined the taxonomic identity of "Hong-do-go-deul-ppae-gi". The morphological traits, geographical distribution, and internal transcribed spacer (ITS) sequences of "Hong-do-go-deul-ppae-gi" were compared to related species within the genus. A morphological examination revealed that the plant was similar to C. lanceolatum in that it has subshrub stems with caudex stout, 8 inner involucrals bracts, and 10 to 12 florets. In contrast, similarities to C. denticulatum were observed in terms of radical leaves deciduous in the flowering period, cauline leaves membranous with acute serrations, and beaked achenes. Furthermore, C. denticulatum and C. lanceolatum grew on Hongdo Island and nearby areas, but C. platyphyllum was not distributed in these areas. The results of morphological and distributional investigations revealed that the Hongdo Island plant should be regarded as C. ×muratagenii, a hybrid between C. denticulatum and C. lanceolatum, not C. ×nakaii, which is a hybrid between C. denticulatum and C. platyphyllum. However, the resolution of the ITS sequences was insufficient such that we could not separate the examined species.