Saxifraga cortusifolia (Saxifragaceae): A new record for the Korean flora from Jejudo Island

Article information

Korean J. Pl. Taxon. 2022;52(4):251-254
Department of Life Sciences, Hallym University, Chuncheon 24252, Korea
1Multidisciplinary Genome Institute, Hallym University, Chuncheon 24252, Korea
2IRUDAIN corporation, Jeju 63102, Korea
3Plant Resources Division, National Institute of Biological Resources, Incheon 22689, Korea
Corresponding author Young-Dong KIM E-mail: ydkim@hallym.ac.kr
Received 2022 December 5; Revised 2022 December 19; Accepted 2022 December 23.

Abstract

Saxifraga cortusifolia Siebold & Zucc. (Saxifragaceae, sect. Irregulares, ser. Rufescentes), a species considered endemic along mountain streams throughout Honshu, Shikoku, and Kyushu in Japan, was discovered as a wild population in the Cheona Valley in Haean-dong, Jeju-si on Jeju-do Island of Korea. The population consisted of three subpopulations occupying narrow areas 10 × 10 m2, 5 × 5 m2, and 10 × 5 m2 in size. The number of individuals in the three subpopulations was confirmed to exceed 100. Most of the individuals were on or below rocks at the edge of the valley. A morphological description, detailed photos, and a key to related taxa in Korea are presented.

INTRODUCTION

Saxifraga L. s. str., the largest genus of Saxifragaceae Juss, contains about two-thirds of the species in the family (Zhmylev, 2004). Recent segregation of Micranthes Haw. from Saxifraga left 13 sections in the genus (Gao et al., 2015; Tkach et al., 2015; Ebersbach et al., 2017a, 2017b). Saxifraga is widely distributed in the arctic and northern temperate region, with centers of diversity in the mountains of Europe, the Himalayan-Tibetan region, eastern Asia, and western North America (Soltis et al., 1996).

Sect. Irregulares Haworth, the ancestral clade of Saxifraga, is usually characterized by bisexual, zygomorphic, 5-merous flowers with white or pink petals as well as herbaceous or leathery leaf blades with a lobed margin and foliar crystals that are present mainly as druses (Pan et al., 2001; Tkach et al., 2015). Section Irregulares includes two series: Stoloniferae J.T. Pan with stolons and Rufescentes J.T. Pan without stolons (Zhang et al., 2020). The species of sect. Irregulares are in Northeast Asia (with one exception in North America), including two species (Saxifraga fortunei Hook. and S. stolonifera Curtis) on the Korean Peninsula (Lee, 1996; Lee, 2003; Kim, 2007).

Saxifraga cortusifolia Siebold & Zucc. (sect. Irregulares ser. Rufescentes) was thought to be a Japanese endemic in the mountainous areas of Honshu, Shikoku, and Kyushu (Wakabayashi, 2001).

During the DNA barcoding project of plant resources in Korea, funded by the National Institute of Biological Resources, a natural population of Saxifraga cortusifolia was discovered in a mountain valley in Haean-dong, Jeju Island (Fig. 1). We here provide a morphological description of the species, detailed photos and a key to related taxa in Korea.

Fig. 1.

Photographs of Saxifraga cortusifolia Siebold & Zucc. A. Habitat. B. Plant habit. C. Leaves, adaxial view. D. Leaves, abaxial view. E. Bract. F. scape. G. Petiole. H. Inflorescence branches. I. Flower.

TAXONOMIC TREATMENT

Saxifraga cortusifolia Siebold & Zucc., Abh. Math.-Phys. Cl. Königl. Bayer. Akad. Wiss. 4(2): 190, 1846; Diptera cortusifolia (Siebold & Zucc.) Losinsk., Izv. Glavn. Bot. Sada S.S.S.R. 27: 601, 1928; Sekika cortusifolia (Siebold & Zucc.) H. Hara, Nakai & Honda, Nov. Fl. Jap. 3: 43, 1939.—TYPE: Japan. Siebold, P. F. von. s.n. (lectotype: M, digital image!).

Saxifraga cortusifolia f. incisa (Takeda) Nemoto, Fl. Japan, Suppl.: 297, 1936.

Saxifraga cortusifolia var. madida Maxim., Bull. Acad. Imp. Sci. St-Pétersbourg 18: 37, 1872; S. madida (Maxim.) Makino, Bot. Mag. (Tokyo) 6: 52, 1892.

Saxifraga madida var. atropurpurea Makino, Bot. Mag. (Tokyo) 24: 30, 1910; S. cortusifolia var. atropurpurea (Makino) Nemoto, Fl. Japan, Suppl.: 297, 1936; S. cortusifolia f. atropurpurea (Makino) Wakab., Fl. Japan 2b: 51, 2001.

Saxifraga madida var. stolonifera Makino, Bot. Mag. (Tokyo) 23: 72, 1909; S. cortusifolia var. stolonifera (Makino) Koidz. & Mayeb., Fl. Austro-Higo.: 25, 1931.

Saxifraga madida var. variegata Nakai, Bot. Mag. (Tokyo) 42: 451, 1928; S. cortusifolia var. variegata (Nakai) Nemoto, Fl. Japan, Suppl.: 297, 1936; S. cortusifolia f. variegata (Nakai) H. Hara, Nakai & Honda, Nov. Fl. Jap. 3: 44, 1939.

Korean name: 탐라바위취 (Tam-la-ba-wi-chwi).

Herbs, perennial, hermaphroditic, to 35 cm tall. Rhizomes short. Stems sparsely pilose. Leaves basal; stipules green or pale purple, lance-ovate to ovate, ca. 4–10 mm long, both surfaces long pilose; petiole 1–17 cm long, pilose; blade widely ovate, widely elliptic, orbicular or reniform, 5- to 10-cleft or rarely lobed, 1.3–9 × 1.5–12 cm, base truncate, cordate or reniform, both surfaces densely or sparsely pilose, adaxial surface green, abaxial surface pale green; lobes ovate to widely ovate, margin doubly serrate. Inflorescences paniculiform cymes, scapose, 4–20 cm long, usually 10- to >50-flowered; scape green, minutely glandular hairy; branches slender, minutely glandular hairy; bracts linear or narrowly triangular, ca. 5 mm long, both surfaces minutely glandular hairy, margin ciliate- pilose. Flowers bisexual, zygomorphic; sepals 5, spreading, ovateoblong, 1–5 mm long, acute or obtuse, both surfaces minutely glandular hairy; petals 5, spreading, white, unequal; 3 upper ones ovate or widely ovate, apex acute or obtuse, distinctly clawed, with yellow spots near base, ca. 3 × 2.5 mm, 2 lower petals oblanceolate, apex narrowly acute or acute, base attenuate, margin entire or toothed near apex, 7–20 × 2.5–4 mm; stamens 10, ca. 5 mm long; anthers yellowish orange just before anthesis; disc prominent, crescent shaped, yellow, surrounding half of base of ovary, usually developed on side of smaller petals; carpels 2; ovary superior, sparsely minutely glandular hairy; styles 2, ca. 3 mm long, elongating slightly after anthesis; stigmas punctiform. Fruits capsules, ovoid, 4–6 mm long. Seeds oblong, ca. 0.7 mm long, narrowly tuberculate and granulate.

Phenology: Flowering September to October, fruiting October to November.

Distribution: Korea, Japan.

Specimens examined: KOREA. Jeju-do: Jeju-si, Haean-dong, Cheona valley, 3 Oct 2019, Yong-In Kim & Jae-seo Shin 2019001, 2019002, 2019003, 2019004, 2019005 (HHU).

JAPAN. Honshu: Tottori Prefecture, Yazu-gun, Wakasa, Mt. Hyonosen, 3 Oct 2019, Young-Sil Kim & Bo-Kyung Song SAF-2019134, SAF-2019135, SAF-2019136, SAF-2019154, SAF-2019155, SAF-2019156 (KB); Hiroshima Prefecture, Yamagata-gun, Sandankyo, 9 Oct 1970, G. Murata et al. 163 (TI); Sandankyo, 1934, T. Makino 12101 (TI); Hyogo Prefecture, Kinosaki-gun, Hidaka-cho, Manba, 5 Oct 1996, N. Fukuoka & N. Kurosaki 9864 (TI); Shisou-gun, Haga-cho, Akazai, 17 Oct 1987, N. Kurosaki & Y. Takita 351 (TI).

Notes: Saxifraga cortusifolia was known as a Japanese endemic species in Honshu, Shikoku, and Kyushu. During this study, a wild population was discovered in the Cheona valley, Haean-dong, Jeju-si, Jeju Island, Korea. The population consisted of three subpopulations occupying narrow areas of 10 × 10 m2, 5 × 5 m2, and 10 × 5 m2. The number of individuals in the three subpopulations was confirmed to be more than 100. Most of the individuals were on or below rocks at the edge of the valley and growing with such plants such as Hedera rhombea (Miq.) Bean, Actaea japonica (Thunb.) Spreng., Parthenocissus tricuspidata (Siebold & Zucc.) Planch., Chrysosplenium japonicum (Maxim.) Makino, Polystichum tripteron (Kunze) C. Presl, Asarum maculatum Nakai, Hepatica asiatica Nakai and Trachelospermum asiaticum (Siebold & Zucc.) Nakai.

Saxifraga cortusifolia can be distinguished from S. stolonifera, a closely related species, by the absence of stolons (vs. presence) and the 5- to 10-cleft (vs. shallowly lobed) leaves, adaxial surface of the leaves uniformly green (vs. dark green and pale along veins).

Key to the species of Saxifraga sect. Irregulares in Korea

  • 1. Upper petals nearly lanceolate, base gradually narrowed, not spotted ········································ S. fortunei

  • 1. Upper petals ovate or widely ovate, base forming a claw, spotted.

    • 2. Stolons present; leaves shallowly lobed, adaxial surface dark green, pale along veins ············································································································································· S. stolonifera

    • 2. Stolons absent; leaves 5–10-cleft or rarely lobed, adaxial surface green ························ S. cortusifolia

Acknowledgements

This study was supported by a grant from the National Institute of Biological Resources of the Republic of Korea (NIBR201905201). We thank Sangbu Kim and two anonymous reviewers for their helpful comments on the manuscript.

Notes

CONFLICTS OF INTEREST

The authors declare that there are no conflicts of interest.

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Fig. 1.

Photographs of Saxifraga cortusifolia Siebold & Zucc. A. Habitat. B. Plant habit. C. Leaves, adaxial view. D. Leaves, abaxial view. E. Bract. F. scape. G. Petiole. H. Inflorescence branches. I. Flower.