J. Jpn. Bot. 91(6): 358–361 (2016) Kenji SUETSUGU: New Locality of the Mycoheterotrophic Orchid Gastrodia fontinalis from Kuroshima Island, Kagoshima Prefecture, Japan Department of Biology, Graduate School of Science, Kobe University, 1-1, Rokkodai, Nada-ku, Kobe, 657-8501, JAPAN E-mail: [email protected] Summary: I found Gastrodia fontinalis T. P. Lin based on a collection from Mt. Pataoerh in Taipei (Orchidaceae) in bamboo forests on Kuroshima County, Taiwan (Lin 1987). This species was Island, the northernmost island of the Ryukyu previously considered as an endemic Taiwanese Islands in Japan. This habitat represents the species. Recently, Suetsugu et al. (2014) found northernmost locality of the species. the species in a bamboo forest on Takeshima Island in Kagoshima Prefecture, Japan. During The genus Gastrodia (Orchidaceae) is a the recent field survey on Kuroshima Island, I group of mycoheterotrophic orchids distributed found additional populations of G. fontinalis in temperate and tropical areas of Madagascar, in bamboo forests from the Island. This habitat Asia, and Oceania (Chung and Hsu 2006). The represents the northernmost locality of the genus, which contains approximately 80 species, species. Here I report the new locality with a is characterized by a fleshy tuber or coralloid description of the specimens from the Island. underground stem, an absence of leaves, the union of sepals and petals, and two mealy Gastrodia fontinalis T. P. Lin, Native pollinia without caudicles (Chen et al. 2009, Orchids of Taiwan 3: 129 (1987). [Fig. 1] Govaerts et al. 2016). Terrestrial, mycoheterotrophic herb. Root G a s t ro d i a shows extraordinary short, densely branching, mostly extending morphological diversity. Some species of sect. from the apex center of the rhizome system. Gastrodia (sensu Schlechter 1911), such as G. Rhizome tuberous, fusiform or cylindrical, 3–13 elata, reach 60–100 cm in height during the cm long, 4–11 mm in diameter, dark brown, anthesis period. In contrast, many species of sect. covered with numerous scales. Inflorescence Codonanthus (Schlechter 1911, Tuyama 1967) erect, dark greenish brown, 10–21 cm long, 3–7 represented by G. verrucosa (G. verrucosa mm in diameter. Bracts ovate, up to 10 mm. group) have inflorescences of only 3–15 cm in Pedicel and ovary up to 15 mm long. Flowers flower but 30–40 cm in fruit, with elongated 1–17, bell-shaped, slightly nodding, resupinate, pedicels (Chung and Hsu 2006). Plants 16–21 mm long, 10–11 mm in diameter. Sepals belonging to the latter group are rarely found and petals united forming a 5-lobed perianth during the flowering season, and thus have tube. Sepals subsimilar, fleshy, 17–21 mm long, not been studied intensively (Tuyama 1982). connate ca. 2/3 the length of the petals, lateral Therefore, our recent botanical surveys have ones connate ca. 3/5 their length with each other, resulted in discoveries of additional members outer surface pale brown, verrucose, margins of sect. Codonanthus in Japan, including new entire; free portion of dorsal sepal straight, distribution records and new taxa (Suetsugu ovate-triangular, retuse, ca. 7 mm long, 8–9 mm 2012, 2013, 2014, 2015, 2016, Suetsugu et al. wide; free portions of lateral sepals spreading, 2012, 2013, 2014). obtuse at apex. Free portions of petals ovate or Gastrodia fontinalis T. P. Lin was described ellipse, ca. 4.5 mm long, 4 mm wide. Lip adnate —358— December 2016 The Journal of Japanese Botany Vol. 91 No. 6 359 Fig. 1. Flowering individual of the mycoheterotrophic orchid Gastrodia fontinalis from Kuroshima Island, Kagoshima Pref., Japan. to column foot, ca. 8 mm long, hypochile with Pref., Kuroshima Island, Katadomori, 14 April 2016, K. 2 red, globose calli; epichile red-brownish, Suetsugu s.n. (OSA); Kuroshima Island, Osato, 16 April ovate-triangular, base contracted, with 6–8 2016, K. Suetsugu s.n. (OSA). ridges elevated on upper portion, with 2 ridges Note: Several hundred flowering individuals extending to the ligulate apex. Column straight, were found in bamboo forests dominated by terete, 8–9 mm long, 2.5 mm wide, white tinged Pleioblastus linearis (Hack.) Nakai throughout with pale green at base; column foot (basal Kuroshima Island. Flowering was observed extension of the column) well-developed; lateral from late March to late April, and fruiting from wings (stelidia) narrow, brown, edges parallel late April to late May. As stated in the above to column, apex acute; rostellum small; stigma description, G. fontinalis of both Takeshima located at base. Anther hemispheric, 1.2 mm in and Kuroshima populations (hereafter Japanese diameter, pollinia 2. Capsule cylindrical, ca. 3 populations) tended to be bigger than Taiwanese cm long, pedicel elongating to ca. 30 cm long in populations (Lin 1987, Leou 2000, Suetsugu fruit. Seeds fusiform, ca. 2.0 mm long. et al. 2014). In addition, the population of G. Specimen examined: JAPAN. Kyushu. Kagoshima fontinalis in Japanese populations was often 360 植物研究雑誌 第 91 巻 第 6 号 2016 年 12 月 characterized by having a large rhizome network to the orchid flora of Taiwan (vi). Taiwania 57: 271– consisting of many rhizomes that have never 277. Leou C. S. 2000. Gastrodia. In: Huang T. C. et al. (eds.), before been found in any Gastrodia species Flora of Taiwan 5: 890–896. Department of Botany, inhabiting Japan or the surrounding areas National Taiwan University, Taipei. (Umata and Yokota 2006, Suetsugu et al. 2014). Lin T. P. 1987. Native Orchids of Taiwan 3. Southern Furthermore, the specimens in Takeshima Island Materials Center, Taipei. were often found to produce a tight root mass Matsuda Y. and Yamada A. 2003. Mycorrhizal morphology of Monotropastrum humile collected from six different complex beneath the rhizome network, just forests in central Japan. Mycologia 95: 993–997. like the root mycorrhizal root ball produced by Schlechter R. 1911. Die Polychondreae (Neottiinae Pfitz.) Monotropastrum globosum H. Andres (Matsuda und ihre systematische Einteilung. Bot. Jahrb. Syst. 45: and Yamada 2003). Given that most species 375–410. Suetsugu K. 2012. A new form of Gastrodia confusa belonging to sect. Codonanthus produce a (Orchidaceae). J. Phytogeogr. Taxon 59: 125–126. small number of straight, slender roots, mostly Suetsugu K. 2013. Gastrodia takesimensis (Orchidaceae), a extending from the apex of the rhizome (e.g., new mycoheterotrophic species from Japan. Ann. Bot. Hsu and Kuo 2010, 2011, Hsu et al. 2012), the Fenn. 50: 375–378. root morphology of the G. fontinalis specimens Suetsugu K. 2014. Gastrodia flexistyloides (Orchidaceae), a new mycoheterotrophic plant with complete found in Japanese populations can be considered cleistogamy from Japan. Phytotaxa 175: 270–274. unique, and it is worth investigating the Suetsugu K. 2015. First record of the mycoheterotrophic Taiwanese population of G. fontinalis also shares orchid Gastrodia uraiensis (Orchidaceae) from the same root morphology for the future study. Yakushima Island, Japan. Acta Phytotax. Geobot. 66: 193–196. This work was supported by a Grant-in-Aid Suetsugu K. 2016. A new color variant of the mycoheterotrophic orchid Gastrodia fontinalis from from the Japan Society for the Promotion of Takeshima Island, Japan. Acta Phytotax. Geobot. 67: Science (15K18470 to K.S.). 55–59. Suetsugu K., Nakama M., Watanabe T., Watanabe H. References and Yokota M. 2012. The northernmost locality of Chen X., Gale S. W. and Cribb P. J. 2009. Gastrodia. In: Gastrodia shimizuana (Orchidaceae). J. Jpn. Bot. 87: Wu Z., Raven P. H. and Hong D. (eds.), Flora of China 62–64. 25: 201–205. Science Press, Beijing and Missouri Suetsugu K., Nakayama M., Watanabe T., Watanabe Botanical Garden, St. Louis. H., Yamamoto T. and Yokota M. 2013. First record Chung S. W. and Hsu T. C. 2006. Gastrodia shimizuana, of the mycoheterotrophic plant Gastrodia clausa a new record of Gastrodia (Orchidaceae) in Taiwan. (Orchidaceae) from Okinawa Island, Ryukyu Islands, Taiwania 51: 50–52. Japan. Acta Phytotax. Geobot. 64: 123–126. Govaerts R., Bernet P., Kratochvil K., Gerlach G., Carr Suetsugu K, Umata H. and Yokota M. 2014. First record G., Alrich P., Pridgeon A. M., Pfahl J., Campacci M. of the mycoheterotrophic orchid Gastrodia fontinalis A., Holland Baptista D., Tigges H., Shaw J., Cribb P. (Orchidaceae) from Takeshima Island, the Ryukyu J., George A., Kreuz K. and Wood J. J. 2016. World Islands, Japan. Taiwania 59: 383–386. Checklist of Orchidaceae. Facilitated by the Royal Tuyama T. 1967. Notes on Gastrodia of Japan (4). J. Jap. Botanic Gardens, Kew (accessed on 31 January 2016). Bot. 42: 230–236. Hsu T. C. and Kuo C. M. 2010. Supplements to the orchid Tuyama T. 1982. A new Gastrodia from the Ryukyus. Acta flora of Taiwan (IV): Four additions to the genus Phytotax. Geobot. 33: 380–382. Gastrodia. Taiwania 55: 243–248. Umata H. and Yokota M. 2006. Comparative Hsu T. C. and Kuo C. M. 2011. Gastrodia albida characterization of two closely related achlorophyllous (Orchidaceae), a new species from Taiwan. Ann. Bot. orchids, Gastrodia nipponica and G. tokaraensis. Res. Fenn. 48: 272–275. Bull. Kagoshima Univ. For. 34: 57–67. Hsu T. C., Chung S. W. and Kuo C. M. 2012. Supplements December 2016 The Journal of Japanese Botany Vol. 91 No. 6 361 末次健司：トカラヤツシロラン（ラン科）を鹿児島県三 島村黒島から記録する 鹿児島県三島村黒島でトカラヤツシロラン（ラン科） く結実個体では同定困難なものが多いため，琉球列島の の開花個体を発見した．これは，台湾，鹿児島県三島村 Codonanthus 節に属する種の分布状況の詳細な検討が望 竹島に次ぐ産地であり，分布の北限となる．オニノヤ まれる． ガラ属の Codonanthus 節に属する種は，開花期間が短 （神戸大学大学院理学研究科）.