Hydrangea minamitanii (H. Ohba) Yahara, 2022

Hirota, Shun K., Yahara, Tetsukazu, Fuse, Kengo, Sato, Hiroyuki, Tagane, Shuichiro, Fujii, Shinji, Minamitani, Tadashi & Suyama, Yoshihisa, 2022, Molecular phylogeny and taxonomy of the Hydrangea serrata complex (Hydrangeaceae) in western Japan, including a new subspecies of H. acuminata from Yakushima, PhytoKeys 188, pp. 49-71 : 49

publication ID	https://dx.doi.org/10.3897/phytokeys.188.64259
persistent identifier	https://treatment.plazi.org/id/5B1A099D-8CB0-5B98-9D42-5868BF71F518
treatment provided by	PhytoKeys by Pensoft
scientific name	Hydrangea minamitanii (H. Ohba) Yahara
status	stat. nov.

Treatment

Hydrangea minamitanii (H. Ohba) Yahara stat. nov.

Hydrangea serrata (Thunb.) Ser. var. minamitanii H. Ohba in J. Jap. Bot. 64: 199 (1989); Ohba & Akiyama, Bull. Natl. Mus. Nat. Sci., Ser. B, 39: 179 (2013). Type. Japan. Miyazaki Pref., Saito City, T. Minamitani 26304 (TI).

Hortensia serrata var. minamitanii (H. Ohba) H. Ohba & S. Akiyama, J. Jap. Bot. 91: 347 (2016).

Japanese name.

Hyuga-ajisai.

Note.

Hydrangea minamitanii and H. acuminata ssp. acuminata often grow close, within 100 m of each other, but the former grows on wet cliffs along streams, and the latter grows on soil along forest margin. Hydrangea minamitanii is distinct from H. acuminata in having leaves glabrous abaxially except tufted hairs at axils of lateral veins, glabrous petioles, and glabrous young shoots (Table 5 View Table 5 ). No intermediates have been discovered in localities where two species grow. Hydrangea minamitanii is similar to H. acuminata subsp. yakushimensis in growing on cliffs along streams and having leaves glabrous on both surfaces except veins and tufted hairs at axils of lateral veins, but they are distinguished by their capsule size (3.9-5.3 mm or longer in H. minamitanii vs. 2.2-2.7 mm in H. acuminata subsp. yakushimensis ) and flower colors (pink or white flowers vs. blue flowers). Whereas H. acuminata subsp. yakushimensis is endemic to the Yakushima island, H. minamitanii is restricted to the mountains of central and eastern Kyushu, mainly in the Miyazaki Prefecture.

Additional specimens examined.

Japan. Miyazaki Pref.: Mt. Osuzu, 500 m elevation, 20 October 1960, with fruits, S. Sako 3285 (KAG 161375!); ditto, 500 m elevation, 28 July 1971, with flowers, S. Hatusima & S. Sako 32643 (KAG 161376!); ditto, 11 July 1976, with flowers, T. Minamitani 22630 (KAG 161378!); Aya Town , 73 m elevation, 24 October 2019, with fruits, S. Tagane 1200 (KAG 128616!) .