Molecular phylogeny and taxonomy of Hosta (Asparagaceae) on Shikoku Island, Japan, including five new species, one new subspecies, and two new status assignments Author Yahara, Tetsukazu https://orcid.org/0000-0001-5105-7152 Kyushu Open University, 744 Motooka, Fukuoka, 819 - 0395, Japan tet.yahara@gmail.com Author Hirota, Shun K. https://orcid.org/0000-0002-6104-1119 Field Science Center, Graduate School of Agricultural Science, Tohoku University, 232 - 3 Yomogida, Naruko-onsen, Osaki, Miyagi 989 - 6711, Japan & Botanical Gardens, Osaka Metropolitan University, 2000 Kisaichi, Katano, Osaki 576 - 0004, Japan Author Fujii, Seiko The Kochi Prefectural Makino Botanical Garden, Godai-san 4200 - 6, Kochi 781 - 8125, Japan Author Kokami, Yasushi The Kochi Prefectural Makino Botanical Garden, Godai-san 4200 - 6, Kochi 781 - 8125, Japan Author Fuse, Kengo Kyushu Open University, 744 Motooka, Fukuoka, 819 - 0395, Japan Author Sato, Hiroyuki https://orcid.org/0000-0001-6003-6492 Kyushu Open University, 744 Motooka, Fukuoka, 819 - 0395, Japan Author Tagane, Shuichiro https://orcid.org/0000-0002-1974-7329 The Kagoshima University Museum, Kagoshima University, 1 - 21 - 30 Korimoto, Kagoshima, 890 - 0065, Japan Author Suyama, Yoshihisa https://orcid.org/0000-0002-3136-5489 Field Science Center, Graduate School of Agricultural Science, Tohoku University, 232 - 3 Yomogida, Naruko-onsen, Osaki, Miyagi 989 - 6711, Japan text PhytoKeys 2023 2023-11-17 235 137 187 http://dx.doi.org/10.3897/phytokeys.235.99140 journal article http://dx.doi.org/10.3897/phytokeys.235.99140 1314-2003-235-137 5C03056135C05D05BC1818F226325D31 4. Hosta shikokiana N. Fujita, Acta Phytotax. Geobot. 27: 93. 1976. Plants on Mt. Higashi-akaishi, Mt. Akaishi, Mt. Nishi-akaishi, and Mt. Shiragayama only. Fig. 11 Type . Japan . Ehime Pref. , Mt. Higashi-akaishi , 7 Aug. 1957 , T. Yamanaka 22475 ( holotype KYO!) . Phenology. Flowering in July and fruiting in August. Distribution and habitat. Japan (Ehime and Kochi Prefectures) (endemic). This species grows in open habitats on the rocky ridgeline of Mt. Higashi-akaishi and its surrounding areas on Shikoku Island. Figure 11. Plants of H. shikokiana A JPN5249 B a flowering plant (photo taken on 12 Jul. 2018 by Se. Fujii; not collected). Scale bars: 10 cm ( A ); 5 cm ( B ). Conservation status. Using criterion D1 for IUCN Red List categories ( IUCN 2012 , IUCN 2022 ), we recommend that this species be classified as VU (Vulnerable) because its population is estimated to be between 250 and 1000. Japanese name. Shikoku-giboshi ( Fujita 1976 ). Additional specimens examined. Japan . Ehime Pref. : Mt. Higashi-akaishi , 15 Jul. 1952 , T. Yamanaka 8901 with flowers (KYO!) ; ditto (as Mt. Akaishi ), 9 Jul. 1928 , G. Koidzumi s.n. with flower buds (KYO!) ; ditto, 1650 m elev., 21 Jun. 2021 , T. Yahara et al. JPN6197 , 6228 , 6239 , 6249 , and 6252 with flower buds (FU!) ; ditto, 1640 m elev., 14 Jul. 1960 , K. Tsuchiya 500 with flowers (KYO!) ; ditto, Mt. Hachimaki (a peak of Mts. Higashi-akaishi ), 22 Jul. 2022 , Se. Fujii JPN9953 , 31 Jul. 2022 , Se. Fujii JPN9954 with flowers (FU!); derived from Mt. Higashi-akaishi , cultivated in Makino Botanical Garden , 8 Apr. 2021 , T. Yahara & Se. Fujii JPN3939-3942 sterile (FU!); between Mt. Higashiakaishi and Mt. Hutatsudake , 1600 m elev., 8 Sep. 1961 , G. Murata 14981 with fruit (KYO!) ; ditto, cultivated stock of G. Murata 14981 , G. Murata s.n. with flowers (KYO!). Kochi Pref. : Mt. Shiraga (cultivated stock), T. Yahara & Se. Fujii JPN3937 , 8 Apr. 2021 , sterile (FU!) ; ditto, Se. Fujii JPN9955 , 23 Jul. 2021 with flowers (FU!) . Note. The following specimens cited by Fujita (1976) are not this species; the specimen from Mt. Kanpu ( Yamawaki s.n. , TI) is H. samukazemontana , and the specimens from Mt. Ishizuchi ( Takahashi & Fujita 226 , KYO; Takafuji s.n. , KYO) are H. polyneuronoides .