Bull. Natl. Mus. Nat. Sci., Ser. B, 46(2), pp. 75–87, May 22, 2020

New Localities of Seed Plants Recorded from the Subtropical Ryukyus of at Island Level Based on Herbarium Data

Goro Kokubugata1, *, Atsushi Ebihara1, Yukiko Saito2, Masaharu Amano3, Atsushi Abe3, Koh Nakamura4, Akiyo Naiki5, Tadashi Kajita5 and Masatsugu Yokota6

1 Department of Botany, National Museum of Nature and Science, 4–1–1 Amakubo, Tsukuba, Ibaraki 305–0005, Japan 2 Department of Science Education, Faculty of Education, University of the Ryukyus, Nishihara, 903–0213, Japan 3 Okinawa Churashima Research Center, Okinawa Churashima Foundation, 888 Ishikawa, Motobu, Okinawa 905–0206, Japan 4 Botanic Garden, Field Science Center for Northern Biosphere, Hokkaido University, 3–8 Chuo-ku, Sapporo 060–0003, Japan 5 Iriomote Station, Tropical Biosphere Research Center, University of the Ryukyus, 870 Uehara, Yaeyama, Taketomi, Okinawa 907–1541, Japan 6 Laboratory of Ecology and Systematics, Faculty of Science, University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa 903–0213, Japan *E-mail: [email protected]

(Received 11 February 2020; accepted 25 March 2020)

Abstract We examined specimens of seed plant taxa collected from the subtropical Ryukyus in three herbaria at the Facility of Education and at Science, University of the Ryukyus, and at National Museum of Nature and Science. This examination led to the discovery of 104 new locali- ties for 79 taxa at island level, 19 of which are treated as Japanese-threatened plants.

Key words: conservation, herbarium specimen, island flora, Ryukyus, seed plant, taxonomy, threatened plants.

Miyako and ), the Daito Islands Introduction and the Senkaku Islands (Fig. 1). The northern The Ryukyu Archipelago (hereafter, the Ryukyus are temperate, and belong to the Sino- Ryukyus) comprises approximately 200 islands Japanese floristic region; whereas the remaining spanning 1,300 km between Kyushu of Japan and four areas are subtropical, and belong to the Taiwan. Biogeographically, the Ryukyus are Southeast Asiatic floristic region (Miyawaki, divided into five areas based on floristic charac- 1977). ters of each island (Tagawa and Miyagi, 1991; Within the subtropical Ryukyus, some islands Yokota, 1997; Kokubugata et al., 2010). These have been the subject of intensive floral surveys five areas are defined as the northern Ryukyus (e.g., Yokota et al., 1997; Abe et al., 2016; Saito (the Osumi Islands and the majority of the et al., 2019). On the other hand, comprehensive Tokara Islands), the central Ryukyus (the remain- floristic surveys of the subtropical Ryukyus were der of the Tokara Islands and the Amami and also conducted by a number of botanists ), the southern Ryukyus (the (Hatusima, 1975; Walker, 1976; Hatusima and Amano, 1994; Shimabuku, 1997), but no surveys © 2020 National Museum of Nature and Science have been conducted since the report produced 76 Goro Kokubugata et al.

Fig. 1. Five biogeographical areas of the Ryukyu Archipelago of Japan. by Shimabuku (1997). In 2015, we begun inves- existing records in relevant major floristic publi- tigating and revising the flora of the subtropical cations (e.g., Hatusima, 1975; Hatusima and Ryukyus, and completed a regional database, the Amano, 1994; Shimabuku, 1997), and noted new Database of Ryukyu Plants (Ryukyu Plant island localities discovered for each taxon. Research Group, 2018 onward). Over the course of the herbarium examinations, we discovered Results and Discussion new localities for seed plants at island level in the subtropical Ryukyus. We examined 53,917 specimens of 2,168 native seed plant taxa (species, subspecies and Materials and Methods varieties) from 187 families. Among all speci- mens collected in the subtropical Ryukyus, we Specimens were identified in the herbaria at found 104 new localities for 79 taxa in 44 fam- the Faculty of Education (URO) and Science ilies (Table 1). (RYU) at the University of the Ryukyus and at The new localities were reported from 27 the National Museum of Nature and Science islands of the subtropical Ryukyus: Kikai-jima (6 (TNS). Following identification, we checked for taxa), Kakeroma-jima (1 taxon), Tokuno-shima New Localities of Plants from the Ryukyus 77

(6 taxa), Okino-erabu-jima (1 taxon), Yoron-jima This small deciduous tree was previously (2 taxa) in the ; Okinawa-jima (10 reported from Ishigaki-jima and Iriomote-jima in taxa), Iheya-jima (9 taxa), Izena-jima (5 taxa), the southern Ryukyus; and from Taiwan, China, Ie-jima (5 taxa), Tokashiki-jima (5 taxa), and the Himalayan region (Hatusima, 1975). A Zamami-jima (1 taxon), Geruma-jima (2 taxa), small number of populations are extant on Ishi- Aka-jima (1 taxon), Tonaki-jima (1 taxon), gaki-jima, although the present status of this spe- Kume-jima (6 taxa) in the Okinawa Islands; cies on Iriomote-jima is unclear (Tateishi and Miyako-jima (4 taxa), Ohgami-jima (1 taxon), Iha, 2018). Irabu-jima (4 taxa), Shimoji-jima (1 taxon), We present a new finding of a specimen of this Kuruma-jima (1 taxon), Tarama-jima (2 taxa) in variety from Miyako-jima in the southern the ; Ishigaki-jima (6 taxa), Ryukyus. This represents a range expansion for Kohama-jima (4 taxa), Iriomote-jima (5 taxa), this taxon, as the previous northernmost occur- Hateruma-jima (3 taxa), Yonaguni-jima (8 taxa) rence was reported ca. 100 km southwest on Ishi- in the Yaeyama Islands; and Uotsuri-jima (4 gaki-jima. taxa) in the Senkaku Islands. Nineteen of the 79 taxa were listed on the Red Conyza leucantha (D.Don) Ludlow et Raven List of the Japanese Ministry of Environment (Asteraceae; RL2019: EN; Fig. 2C) (2019; hereafter, RL2019; Table 1). Out of these, This annual or biennial herb has been reported we describe and discuss here conservation, tax- from Iriomote-jima and Yonaguni-jima in the onomic and biogeographic features of 12 taxa: southern Ryukyus; and widely distributes in Tai- five critically endangered (CR), two endangered wan, China, Southeast Asia, and Australia (EN), and five vulnerable (VU) species. (Yokota and Ikehara, 2018). We discovered a new occurrence of this spe- Deeringia polysperma (Roxb.) Moq. (Amaran- cies on Ishigaki-jima of the southern Ryukyus, thaceae; RL2019: CR; Fig. 2A) which is the third record from Japan at island This evergreen vine-shrub has been reported level, and represents the northernmost population from the Miyako (Miyako-jima, Ohgami-jima of this species. and Kuruma-jima) and Yaeyama Islands (Ishi- gaki-jima, Iriomote-jima, Kohama-jima, and Cordia aspera G.Forst. subsp. kanehirae Hateruma-jima) in the southern Ryukyus; and (Hayata) H.Y.Liu (Boraginaceae; RL2019: CR; from Taiwan, China, India, and Malaysia (Yokota Fig. 2D) et al., 2018a). The populations found on the This small deciduous tree was previously Miyako Islands represent the northernmost reported from Ishigaki-jima, Iriomote-jima in the known distribution range of this species. Yaeyama Islands, and Uotsuri-jima in the Sen- We report a new locality for this species on kaku Islands (Yonekura, 2017). Yonaguni-jima of the Yaeyama Islands. Hatusima We report a new record of this subspecies (1975) previously stated that the Ryukyus plants from Yonaguni-jima in the Yaeyama Islands, are morphologically distinct in terms of both leaf which is situated near Taiwan. Some taxonomists number and flower size from those found outside treat the Ryukyu plants as C. cumingiana Vidal, of Japan. It is taxonomically important to investi- which is distributed in Japan, Taiwan and the gate these morphological characters on the plant Philippines (e.g., Hatusima, 1975). Therefore, from Yonaguni-jima being closest to Taiwan in this record from Yonaguni-jima is important for the Ryukyus. determining the taxonomic and phylogeographi- cal relationship between the Ryukyus and Tai- Rhus javanica L. var. javanica (Anacardiaceae; wan. RL2019: CR; Fig. 2B) 78 Goro Kokubugata et al. date Collection Aug 9, 1954 Nov 2, 2012 Sept 26, 1977 June, 1947 Mar 9, 1993 July 4, 1967 May 5, 1975 Mar 27, 1972 Nov 22, 1937 Apr 15, 1993 Aug 16, 1969 July 15, 1970 Apr 14, 1966 Unknown Apr 3, 1971 Apr 16, 1975 Mar 9, 1971 Apr 14, 2005 Apr 14, 2005 Oct 12, 1972 Apr 16, 1975 June 4, 1978 July 27, 1951 Nov 4, 2004 Dec 4, 1973 June 21, 1975 Apr 12, 1966 2016 Jan 11, Mar 9, 1995 1974 Dec 11, 1974 Dec 11, 1974 Dec 11, Dec 28, 1957 May 16, 1974 June 25, 2007 Aug, 1922 Aug, 1922 Oct 8, 1974 Sept 26, 1975 Apr 3, 1971 July 27, 1950

K. Yasuda 6224 , TNS1028706) K. Yasuda , RYU37379)

, TNS63609) , RYU36234) , RYU36217) , RYU10564) H. Migo 26919 , TNS373842) S. Isa s.n. , RYU12792) I. Inoue s.n. , RYU18082)

K. Shinjo 12782 , URO101604) K. Shinjo 5273 , URO105165) T. Tamaki & Y. Niiro s.n. , RYU1550) Niiro & Y. Tamaki T. Y. Miyagi & T. Kabashima 4450 , RYU21836) Miyagi & T. Y. T. Takara s.n. , RYU41967) Takara T. G. Ikeda 4219 , RYU41616) Z. Nakasone s.n. , TNS58115) T. Yamazaki 624 , TNS325236) Yamazaki T. Y. Miyagi 7079 Y. H. Higa s.n. , RYU28200) S. Sakaguchi s.n. , TNS220004) Y. Niiro s.n. , RYU18897) Niiro Y. S. Sakaguchi 18 S. Sakaguchi s.n. , TNS63610) T. Amano s.n. , RYU26592) T. J. Miyagi s.n. Y. Jotani s.n. , TNS829744) Y. Jotani s.n. , TNS829745) Y. Jotani s.n. , TNS829746) Y. K. Yoshinaga 171 , RYU46639) K. Yoshinaga K. Yoshinaga 423 , RYU35159) K. Yoshinaga Y. Miyagi & S. Hatusima 39965 Y. S. Tamaki & Y. Niiro s.n. , RYU5128) Niiro & Y. S. Tamaki Y. Miyagi & S. Hatusima 39975 Y. Y. Niiro & S. Tamaki s.n. , RYU2698) & S. Tamaki Niiro Y. personal no. , herbarium of voucher specimen) M. Izu & Y. Nakamoto 820 , URO116121) , M. Izu & Y. Locality ( , E. Nakada & S. Hatusima s.n. RYU16196) Y. Kobana 10591 , TNS1091824) ( Y. , H. Setoguchi & N. Nomura 4006 TNS1029052) ( K. Yasuda , H. Setoguchi & N. Nomura 4006 TNS1135143) ( K. Yasuda K. Yasuda 2980 , TNS1028537) ( K. Yasuda T. Amano 6696 , TNS264876) ( T. Y. Miyagi ( Y. G. Kokubugata & M. Tabata 18999 , TNS1265821) ( G. Kokubugata & M. Tabata Y. Tateishi ( H. Ogawa , Y. M. Yokota 15319 , TNS1183783) ( M. Yokota Okinawa Islands, Kume-jima, Gima-gawa River. Central Ryukyus, Southern Ryukyus, Miyako Islands, Kuruma-jima. ( Southern Ryukyus, s.n. , RYU25654) Islands, Ishigaki-jima, Mt. Nosoko-dake. ( E. Takamine Yaeyama Southern Ryukyus, ( S. Nakamine s.n. , S116456) Tonokura. Okinawa Islands, Okinawa-jima, -shi, Central Ryukyus, Southern Ryukyus, Yaeyama Islands, Yonaguni-jima. ( Yonaguni-jima. Islands, Yaeyama Southern Ryukyus, Southern Ryukyus, Yaeyama Islands, Yonaguni-jima. ( Yonaguni-jima. Islands, Yaeyama Southern Ryukyus, Amami Islands, Kikai-jima. ( Central Ryukyus, Southern Ryukyus, Yaeyama Islands, Yonaguni-jima. ( Yonaguni-jima. Islands, Yaeyama Southern Ryukyus, Southern Ryukyus, Miyako Islands, Miyako-jima. ( Southern Ryukyus, Southern Ryukyus, Yaeyama Islands, Iriomote-jima, Ohtomi Forest Road. Yaeyama Southern Ryukyus, Southern Ryukyus, Miyako Islands, Miyako-jima, Shimajiri. ( Southern Ryukyus, Southern Ryukyus, Miyako Islands, Miyako-jima, Ohura. ( Southern Ryukyus, Central Ryukyus, Amami Islands, Tokuno-shima, Omonawa. ( Tokuno-shima, Amami Islands, Central Ryukyus, Central Ryukyus, Okinawa Islands, Kume-jima. ( Central Ryukyus, Senkaku Islands, Uotsuri-jima. ( Senkaku Islands, Uotsuri-jima. ( Okinawa Islands, Izena-jima. ( Central Ryukyus, Southern Ryukyus, Yaeyama Islands, Ishigaki-jima, Yonehara. Yonehara. Islands, Ishigaki-jima, Yaeyama Southern Ryukyus, Yonehara. Islands, Ishigaki-jima, Yaeyama Southern Ryukyus, Central Ryukyus, Okinawa Islands, Geruma-jima. ( Central Ryukyus, Senkaku Islands, Uotsuri-jima. ( Central Ryukyus, Okinawa Islands, Okinawa-jima. ( Central Ryukyus, Southern Ryukyus, Yaeyama Islands, Ishigaki-jima, Nagura-gawa River. Islands, Ishigaki-jima, Nagura-gawa River. Yaeyama Southern Ryukyus, Central Ryukyus, Okinawa Islands, Okinawa-jima, Higashi-son, Kesaji Mangrove. Central Ryukyus, Southern Ryukyus, Miyako Islands, Shimoji-jima, Kamiji Southern Ryukyus, ( H. Migo s.n. , TNS73942) Takise. Tokuno-shima, Amami Islands, Central Ryukyus, Central Ryukyus, Amami Islands, Kikai-jima. ( Central Ryukyus, Akitoku. Amami Islands, Kakeroma-jima, Central Ryukyus, Central Ryukyus, Amami Islands, Yoron-jima. ( Yoron-jima. Amami Islands, Central Ryukyus, ( Yoron-jima. Amami Islands, Central Ryukyus, Central Ryukyus, Okinawa Islands, Ie-jima, Ie-son Youth Village. Village. Youth Okinawa Islands, Ie-jima, Ie-son Central Ryukyus, ( Yoron-jima. Amami Islands, Central Ryukyus, Central Ryukyus, Okinawa Islands, Tokashiki-jima. ( Tokashiki-jima. Okinawa Islands, Central Ryukyus, Okinawa Islands, Kume-jima. ( Central Ryukyus, Southern Ryukyus, Miyako Islands, Irabu-jima. ( Southern Ryukyus, Southern Ryukyus, Miyako Islands, Irabu-jima. ( Southern Ryukyus, ( Tonaki-jima. Okinawa Islands, Central Ryukyus, ( Tarama-jima. Miyako Islands, Southern Ryukyus, Southern Ryukyus, Yaeyama Islands, Hateruma-jima, Takana-zaki. ( Takana-zaki. Islands, Hateruma-jima, Yaeyama Southern Ryukyus, Senkaku Islands, Uotsuri-jima. ( Southern Ryukyus, Miyako Islands, Irabu-jima. ( Southern Ryukyus, * status RL2019 CR CR CR NT EN Japanese common name Okinawa-hainezu Indo-himo-kazura Ko-menamomi Togemino-inuchisha Ogino-tsume Okinawa-juzusuge Taiwan-fushinoki Kakiba-chishanoki Ryukyu-urokomari Aki-kasasuge Kenashi-tsurumorinka Kyuri-gusa Ryukyu-mochi Oh-shiibamochi Kana-mugura Isoyama-tentsuki No-chidome Hamanindo Okinawa-chidomegusa Ryukyu-tsuru-umemodoki Okinawa-haguma Horutokazura Atsuba-asagao Ki-karasu-uri Niitaka-yomogi Kazuzaki-kozorina Ko-yabutabako Nebari-izu-hahako (Koidz.) Satake (Ohwi) T.Yamaz.

(Miq.) Kitam. T.Koyama (Hayata) H.Y.Liu Species kanehirae Hayata var. okinawensis (Hayata) Kitam. Hayata var. Maxim. var. japonica Maxim. var. (Vahl) Nees (Vahl) (Roxb.) Druce Hook. et Arn. var. lutchuensis Arn. var. Hook. et Hatus. ex T.Yamaz. Hatus. ex glabrescens Maxim. var. (D.Don) Ludlow et Raven Loes. L. var. javanica L. var. maritima Honda Lam. var. tuberifera sibthorpioides Lam. var. (L.) Vahl var. sieboldii var. Vahl ferruginea (L.) (Makino) Makino glabrescens macroclinidioides henryi Prain liukiuensis Loes. warburgii (Miq. ex Franch. et Sav.) Ohwi (Miq. ex Franch. et Sav.) Juniperus taxifolia Deeringia polysperma (Roxb.) Moq. Sigesbeckia Steud. var. fastigiata ischnostachya Steud. var. Carex Rhus javanica aspera G.Forst. subsp. Cordia dichotoma G.Forst. Cordia salicifolia Hygrophila Lepidagathis inaequalis C.B.Clarke ex Elmer nemostachys Steud. Carex tanakae Tylophora (Trevir.) Benth. ex Hemsl. peduncularis (Trevir.) Trigonotis Fimbristylis Ilex (Lour.) Merr. Humulus scandens (Lour.) Ilex Hydrocotyle Arn. Lonicera affinis Hook. et Celastrus kusanoi Hayata Hydrocotyle Ainsliaea Erycibe (Vahl) Griseb. Ipomoea imperati (Vahl) Artemisia morrisonensis Hayata kirilowii Trichosanthes Blumea lanceolaria Carpesium cernuum L. Conyza leucantha Family Table. Table. 1. Japan New record of seed plants at island level and their voucher specimens locality information in the subtropical Ryukyus, Cupressaceae Amaranthaceae Cyperaceae Anacardiaceae Boraginaceae Acanthaceae Apocynaceae Aquifoliaceae Cannabaceae Araliaceae Caprifoliaceae Celastraceae Asteraceae Convolvulaceae Cucurbitaceae New Localities of Plants from the Ryukyus 79 date Collection July 22, 1951 Jan 17, 2005 Jan 17, 2005 Jan 17, 2005 Mar 2, 1957 Sept 26, 1938 Sept 29, 1973 May 16, 1974 Aug 22, 1942 Apr 16, 1952 July 6, 2007 Dec 29, 1956 Aug 23, 1973 May 6, 1973 Sept 15, 1977 May 21, 1972 July 9, 1975 Feb 12, 1975 Nov 4, 2004 July 24, 1938 Mar 26, 1998 Dec 20, 1963 Oct 19, 2001 June 28, 1996 June 28, 1996 Oct 22, 2012 July 12, 1973 Sept 15, 1977 Aug 23, 1973 Sept 18, 1994 Apr 12, 1996 June 12, 2012 Sept 30, 1973 Feb 7, 2010 Aug 9, 1977 Jan 8, 1958 May 16, 1974 Feb 15, 1974 July 7, 1975 , RYU9052) , URO102461) , RYU34181) S. Tawada 979 , TNS231834) S. Tawada Takamine 148 , TNS234709) Takamine M. Amano 1466 , URO110034)

T. Kitahara 6264 , TNS1113778) T.

F. Maekawa s.n. , TNS882512) F. K. Shinjo 729 , URO102682) S. Hatusima 33988 , RYU4630) Y. Miyagi 6722 , RYU35912) Y. S. Hatusima , H. Kanai K. Shimabuku K. Shinjo & Y. Tateishi 10943 Tateishi K. Shinjo & Y. Y. Miyagi 6570 , RYU37685) Y.

Y. Miyagi & T. Kabashima 4789 , RYU22151) Miyagi & T. Y. Y. Miyagi & S. Oyadomari 1265 Y. Y. Miyagi & T. Kabashima 4452 , RYU21745) Miyagi & T. Y. T. Yamazaki & H. Usui 2086 , TNS161566) Yamazaki T.

E. Sugama s.n. , URO110036) K. Shinjo 2030 , URO114592) E. Nakada s.n. , RYU11652) E. Nakata s.n. , RYU11654) K. Yoshinaga 1427 , RYU40311) K. Yoshinaga K. Yoshinaga 1415 , RYU40367) K. Yoshinaga K. Yoshinaga 1327 , RYU40347) K. Yoshinaga S. Tawada 75 , TNS101578) S. Tawada personal no. , herbarium of voucher specimen) , & M. Furuse 732234 , TNS297054) Locality ( T. Yamashiro & E. Tamaki 43517 , URO109947) & E. Tamaki Yamashiro , S. Matsumura T. 43518 , URO109953) & E. Tamaki Yamashiro , S. Matsumura T. , E. Nakata Y. Miyagi & E. Nakata 35781 , RYU14850) ( S. Hatusima , Y. K. Yasuda 2980 , TNS1028538) ( K. Yasuda G. Kokubugata & M. Yokota 14163 , TNS1140521) ( G. Kokubugata & M. Yokota , A. Abe 15306 , TNS1183781) ( G. Kokubugata , M. Yokota Y. Tateishi ( Y. Tateishi ( Y. Y. Tateishi, H. Ogawa & A. Takada 40298 , URO110037) A. Takada H. Ogawa & Tateishi, ( Y. Y. Miyagi Y. M. Yokota & H. Yamashita 12477 , TNS01103877) & H. Yamashita ( G. Kokubugata , M. Yokota T. Amano s.n. , RYU27724) Okinawa Islands, Okinawa-jima, Higashi-son, Kesaji. ( T. Central Ryukyus, 3354 , TNS1028546) ( K. Yasuda Okinawa Islands, Kume-jima, Shirase-gawa River. Central Ryukyus, 3354 , TNS1028547) ( K. Yasuda Okinawa Islands, Kume-jima, Shirase-gawa River. Central Ryukyus, 3354 , TNS1028548) ( K. Yasuda Okinawa Islands, Kume-jima, Shirase-gawa River. Central Ryukyus, Islands, Ishigaki-jima, Mt. Omoto-dake. ( K. Shinjo 1225 , URO108754) Yaeyama Southern Ryukyus, 385 , TNS231284) Taira Okinawa Islands, Okinawa-jima, Kunigami-son, Oku. ( Y. Central Ryukyus, Islands, Yonaguni-jima. Yaeyama Southern Ryukyus, ( Tokashiki-jima. Okinawa Islands, Central Ryukyus, Senkaku Islands, Uotsuri-jima. ( Southern Ryukyus, Yaeyama Islands, Iriomote-jima, Mihara. ( Yaeyama Southern Ryukyus, Miyako Islands, Miyako-jima, Mt. Ohno-yama. ( Southern Ryukyus, Okinawa Islands, Iheya-jima, Dana. ( Central Ryukyus, ( Tokashiki-jima. Okinawa Islands, Central Ryukyus, Okinawa Islands, Ie-jima, Ie Beach. ( Central Ryukyus, Islands, Hateruma-jima. ( Yaeyama Southern Ryukyus, Central Ryukyus, Okinawa Islands, Izena-jima. ( Central Ryukyus, Amami Islands, Kikai-jima. ( Central Ryukyus, Y. Miyagi & S. Hatusima 39551 ( Y. Tokuno-shima. Amami Islands, Central Ryukyus, Southern Ryukyus, Yaeyama Islands, Ishigaki-jima, Nagura-gawa River. Islands, Ishigaki-jima, Nagura-gawa River. Yaeyama Southern Ryukyus, Islands, Ishigaki-jima, Sakieda. (E. Yaeyama Southern Ryukyus, Southern Ryukyus, Yaeyama Islands, Kohama-jima. ( Yaeyama Southern Ryukyus, Okinawa Islands, Okinawa-jima. ( Central Ryukyus, Amami Islands, Kikai-jima. ( Central Ryukyus, Southern Ryukyus, Yaeyama Islands, Yonaguni-jima, Higawa. Yonaguni-jima, Islands, Yaeyama Southern Ryukyus, Okinawa Islands, Okinawa-jima, Hentona. Central Ryukyus, Okinawa Islands, Okinawa-jima, Hentona. Central Ryukyus, Miyako Islands, Ohgami-jima. Southern Ryukyus, Y. Jotani & S. Masuda s.n. , TNS829262) ( Y. Tokuno-shima. Amami Islands, Central Ryukyus, Central Ryukyus, Okinawa Islands, Izena-jima. ( Central Ryukyus, Southern Ryukyus, Miyako Islands, Irabu-jima, ground of Sawada Worker Recreation Center. Recreation Center. Worker Miyako Islands, Irabu-jima, ground of Sawada Southern Ryukyus, Southern Ryukyus, Miyako Islands, Irabu-jima. ( Southern Ryukyus, Miyako Islands, Irabu-jima, Sabaoki Park. ( Southern Ryukyus, Southern Ryukyus, Yaeyama Islands, Yonaguni-jima. ( Yonaguni-jima. Islands, Yaeyama Southern Ryukyus, seaside of Ohtsu-gawa River. Tokuno-shima, Amami Islands, Central Ryukyus, Central Ryukyus, Amami Islands, Kikai-jima. ( Central Ryukyus, Central Ryukyus, Okinawa Islands, Iheya-jima. ( Central Ryukyus, ( Tokashiki-jima. Okinawa Islands, Central Ryukyus, Okinawa Islands, Kume-jima, Oh-dake. ( Central Ryukyus, Southern Ryukyus, Yaeyama Islands, Kohama-jima. ( Yaeyama Southern Ryukyus, * status RL2019 VU CR EN NT NT NT VU Table. 1. Table. Continued. Japanese common name Tsukushi-tentsuki Nebikigusa Suisya-hoshikusa Igusa Ke-shibanikkei Sagaribana Kogai-zekisho Kurogaya Shirotsubu Aogashi Tsuru-urikusa Inukoju Oh-hinji-gayatsuri Hozuki-hagi Mizu-nekono Hinji-gayatsuri Tokiwa-yabuhagi Waniguchi-modama Amami-arakashi Nangoku-aoki Ryukyu-hanaikada Umi-shobu Koke-otogiri Koidz. Species ovoidea amamiana (Hatus.) Hatus. ex H.Ohba Engl. var. pseudodaphnoides Hatus. Engl. var. (R.Br.) Kunth (R.Br.) (Lour.) Kuntze (Lour.) J.Gay ex Laharpe (Thunb.) F.Dietr. subsp. (Thunb.) F.Dietr. Siebold et Zucc. ex Blume var. japonica Siebold et Zucc. ex Blume var. (Willd.) DC. subsp. gigantea (Willd.) (Buchenau) Nakai Thunb. var. Thunb. var. (Hatus.) H.Hara et S.Kuros. Ohwi tashiroana bonduc (L.) Roxb. truncatum Buch.-Ham. ex Mart. japonica liukiuensis Juncus decipiens Cinnamomum doederleinii Barringtonia racemosa (L.) Spreng. Fimbristylis T.Koyama Machaerina rubiginosa (Sol. ex G.Forst.) Eriocaulon Caesalpinia concolor Lindl. Torenia Gahnia tristis Nees Juncus leschenaultii Machilus japonica (Thunb.) C.Y.Wu et H.W.Li Mosla scabra (Thunb.) C.Y.Wu Lipocarpha chinensis (Osbeck) Kern (Poir.) Bakh.f. ex van Meeuwen (Poir.) Christia obcordata Pogostemon stellatus Lipocarpha microcephala A.Gray ex Benth. Desmodium leptopus Mucuna gigantea Thunb. var. glauca Thunb. var. Quercus Aucuba japonica Helwingia (L.f.) Rich. ex Steud. Enhalus acoroides Hypericum laxum (Blume) Koidz. Family Juncaceae Lauraceae Lecythidaceae Eriocaulaceae Fabaceae Linderniaceae Lamiaceae Fagaceae Garryaceae Helwingiaceae Hydrocharitaceae Hypericaceae 80 Goro Kokubugata et al. date Collection Mar 13, 2007 June 1, 1973 Dec 21, 2004 Dec 21, 2004 Mar 24, 2007 Mar 13, 2007 Oct 24, 2008 Aug 12, 1977 July 23, 1973 Aug 12, 1977 July 9, 1975 Sept 14, 1973 July 24, 1973 July 24, 1973 Apr, 1971 Apr, June 19, 1938 June 10, 2004 Feb 4, 2007 Nov 8, 1970 Apr 22, 1973 May 22, 1970 Aug, 1970 Dec 10, 1974 July 27, 1950 July, 1919 July, Apr 19, 1954 Apr 29, 1939 July 8, 1978 July 24, 1973 Oct 3, 1973 May 5, 1981 Dec 28, 1958 Aug 15, 1960 Aug 29, 1970 July 7, 1975 May 4, 1995 Mar 9, 1971 Dec 24, 1971 Dec 24, 1971 Apr 19, 1998 Dec 21, 2004 , TNS369367) , RYU3050) , TNS318258) (S. Tamaki s.n. , RYU2887) (S. Tamaki

, RYU37649) M. Furuse 3012 , RYU11158)

K. Yasuda 2720 , TNS1028241) K. Yasuda , RYU44160) , RYU42957) , RYU11178) T. Amano 7298 , TNS116325) T. , RYU38103) Miyagi 6711 Y. Y. Jotani 38537 , TNS849315) Y.

S. Kurata & T. Nakaike 330 S. Kurata & T. Y. Miyagi 6535 Y. K. Shimabuku 4188 , RYU41284) Y. Niiro & Y. Miyagi 3071 & Y. Niiro Y. Y. Niiro s.n. , RYU2832) Niiro Y. C. Shiroma s.n. , TNS1065846) C. Shiroma T. Amano s.n. , RYU25348) T. S. Hatusima & al. 35089 , RYU11694) S. Hatusima & al. 35085 , RYU11698) , RYU11726) S. Hatusima & al. 35117 S. Kayô s.n. , RYU19562) S. Hatusima & al. 35107 , RYU11730) Y. Niiro s.n. , RYU19855) Niiro Y. S. Kayô s.n. , RYU10349) J. Miyagi s.n. J. Haginiwa 016754 , TNS966754) J. Haginiwa 016755 , TNS966755) Y. Miyagi 7751 Y. Y. Miyagi 7931 Y. S. Kayô s.n. , RYU20672) S. Kayô s.n. , RYU19560) , URO104569) personal no. , herbarium of voucher specimen) Locality ( M. Yokota & K. Yasuda 5403 , TNS9519036) & K. Yasuda ( G. Kokubugata , M. Yokota 5404 , TNS9519037) & K. Yasuda ( G. Kokubugata , M. Yokota H. Tomiyama & T. Kitahara 5395 , TNS1119720) & T. , G. Kokubugata S. Higa H. Tomiyama , M. Yokota ( K. Yasuda , TNS9543099) ( G. Kokubugata 11151 S. Matsushima & T. Kitahara 5260 , TNS1114499) Kitahara T. , S. Matsushima & , S. Higa H. Tomiyama , M. Yokota ( K. Yasuda T. Kanasiro s.n. , RYU25419) Kanasiro ( T. Y. Miyagi & E. Nakata 722362 ( S. Hatusima , H. Kanai K. Shimabuku Y. K. Shinjo & Y. Tateishi 790 Tateishi ( K. Shinjo & Y. M. Yokota & K. Yasuda 5458 , TNS9519088) & K. Yasuda ( G. Kokubugata , M. Yokota K. Yasuda 5376 , TNS1119995) ( K. Yasuda Aira-gawa River. Islands, Iriomote-jima, Yaeyama Southern Ryukyus, Islands, Iriomote-jima. ( Yaeyama Southern Ryukyus, Islands, Iriomote-jima, Mt. Komi-dake. Yaeyama Southern Ryukyus, Islands, Iriomote-jima, Mt. Komi-dake. Yaeyama Southern Ryukyus, Islands, Iriomote-jima, Udara-gawa, River. Yaeyama Southern Ryukyus, , TNS1119994) 5376 ( K. Yasuda Aira-gawa River. Islands, Iriomote-jima, Yaeyama Southern Ryukyus, Islands, Iriomote-jima, Urauchi-gawa River. Yaeyama Southern Ryukyus, Central Ryukyus, Okinawa Islands, Aka-jima. ( Okinawa Islands, Central Ryukyus, Central Ryukyus, Okinawa Islands, Iheya-jima. ( Central Ryukyus, Islands, Hateruma-jima. ( Yaeyama Southern Ryukyus, Central Ryukyus, Okinawa Islands, Iheya-jima. ( Central Ryukyus, Aka-jima. ( Okinawa Islands, Central Ryukyus, Central Ryukyus, Okinawa Islands, Iheya-jima. ( Central Ryukyus, Central Ryukyus, Okinawa Islands, Zamami-jima. ( Central Ryukyus, Okinawa Islands, Ie-jima. ( Central Ryukyus, Southern Ryukyus, Yaeyama Islands, Iriomote-jima, Hoshidate. ( Yaeyama Southern Ryukyus, Y. Taira 278 , TNS233978) Taira ( Y. Tsuboya. Okinawa Islands, Okinawa-jima, Naha-shi, Central Ryukyus, Southern Ryukyus, Yaeyama Islands, Ishigaki-jima, Nagura-gawa River. Islands, Ishigaki-jima, Nagura-gawa River. Yaeyama Southern Ryukyus, Central Ryukyus, Okinawa Islands, Okinawa-jima, Mt. Yonaha-dake. Yonaha-dake. Okinawa Islands, Okinawa-jima, Mt. Central Ryukyus, Southern Ryukyus, Yaeyama Islands, Iriomote-jima, Shirahama. ( Yaeyama Southern Ryukyus, Okinawa Islands, Ie-jima. ( Central Ryukyus, Okinawa Islands, Iheya-jima. ( Central Ryukyus, 39004 , RYU31399) Miyagi Y. ( S. Hatusima & Islands, Okino-erabu-jima. Amami Ryukyus, Central Southern Ryukyus, Miyako Islands, Irabu-jima. ( Southern Ryukyus, Southern Ryukyus, Yaeyama Islands, Ishigaki-jima, Kabira. ( Yaeyama Southern Ryukyus, Central Ryukyus, Okinawa Islands, Kume-jima. ( Central Ryukyus, Central Ryukyus, Okinawa Islands, Okinawa-jima, Nakijin-son, Wakugawa. Wakugawa. Okinawa Islands, Okinawa-jima, Nakijin-son, Central Ryukyus, Central Ryukyus, Okinawa Islands, Tokashiki-jima. ( Tokashiki-jima. Okinawa Islands, Central Ryukyus, Central Ryukyus, Okinawa Islands, Iheya-jima. ( Central Ryukyus, Southern Ryukyus, Yaeyama Islands, Yonaguni-jima. ( Yonaguni-jima. Islands, Yaeyama Southern Ryukyus, Southern Ryukyus, Yaeyama Islands, Yonaguni-jima. Islands, Yonaguni-jima. Yaeyama Southern Ryukyus, Central Ryukyus, Okinawa Islands, Iheya-jima. ( Central Ryukyus, Central Ryukyus, Okinawa Islands, Geruma-jima. ( Central Ryukyus, Central Ryukyus, Okinawa Islands, Iheya-jima. ( Central Ryukyus, Southern Ryukyus, Yaeyama Islands, Kohama-jima. ( Yaeyama Southern Ryukyus, Central Ryukyus, Okinawa Islands, Iheya-jima, Mt. Kuba-yama. Central Ryukyus, Okinawa Islands, Izena-jima. ( Central Ryukyus, Central Ryukyus, Amami Islands, Yoron-jima. ( Yoron-jima. Amami Islands, Central Ryukyus, Akaren. ( H. Murakami 437 , TNS689342) Amami Islands, Kikai-jima, Central Ryukyus, Central Ryukyus, Amami Islands, Yoron-jima. ( Yoron-jima. Amami Islands, Central Ryukyus, Southern Ryukyus, Yaeyama Islands, Iriomote-jima, Mt. Komi-dake. Yaeyama Southern Ryukyus, * status RL2019 NT NT CR VU VU VU Table. 1. Table. Continued. Japanese common name Suzumeno-hakobe Hime-chigozasa Kirun-kankonoki Hitotaba-mehishiba Taiwan-ashikaki Azegaya Horai-tsuzurafuji Sasagaya Numeri-gusa Hime-shiroasaza Mamakono-shirinugui Ohba-ako Bakuchinoki Hime-itabi Ryukyu-ichigo Okinawa-sokei Ke-mizukimbai Niraba-ran Kinu-ran Munin-kikeman Amami-hisakaki (Koidz.) Ohwi Species Hayata (L.) Schltr. (Meisn.) H.Gross (L.) Chase var. oryzetorum (Makino) Ohwi (L.) Chase var. lanceolatum chinensis (L.) Nees strateumatica minima (K.D.Koenig ex Retz.) Merr. Microcarpaea Cyrtococcum patens (L.) A.Camus Glochidion (Fisch. ex Trin.) Büse Trin.) Digitaria pruriens (Fisch. ex Leersia hexandra Sw. Pericampylus formosanus Diels Leptochloa japonicum (Miq.) Koidz. Microstegium (H.Lév.) H.Hara (H.Lév.) Nymphoides coreana Persicaria senticosa Sacciolepis indica Ficus caulocarpa (Miq.) Miq. Prunus zippeliana Miq. Maxim. Ficus thunbergii Rubus grayanus Maxim. Jasminum superfluum Koidz. Ludwigia adscendens (L.) H.Hara parviflora R.Br. Microtis Zeuxine Siebold et Zucc. var. brachystyla Siebold et Zucc. var. Corydalis heterocarpa Eurya osimensis Masam. Family Phrymaceae Poaceae Phyllanthaceae Menispermaceae Menyanthaceae Polygonaceae Moraceae Rosaceae Oleaceae Onagraceae Orchidaceae Papaveraceae Pentaphylacaceae New Localities of Plants from the Ryukyus 81

Fimbristylis dichotoma (L.) Vahl subsp. podo-

date carpa (Nees et Meyen) T.Koyama (Cyperaceae; Collection Sept 29, 1973 Sept 29, 1973 Sept 26, 1975 July 11, 1973 July 11, 1973 July 11, Aug 29, 1970 Mar 26, 1998 May 4, 1974 Aug 9, 1894 RL2019: VU; Fig. 3A) This perennial sedge has been reported from Okinawa-jima in the central Ryukyus and Ish- igaki-jima in the southern Ryukyus; from , URO112873) Kyushu of Japan; and is widely distributed in , RYU21898) India, Malaysia, and the Pacific Islands (Yokota and Nakata, 2018). Three and one populations

M. Kugai s.n. , RYU6327) are respectively known from Okinawa-jima and Ishigaki-jima at present (Yokota and Nakata, K. Shinjo & Y. Tateishi 10954 Tateishi K. Shinjo & Y.

T. Ito 168 , TNS382406) T. 2018). Y. Miyagi s.n. , RYU37424) Y. We report a new locality for this species on S. Hatusima & Y. Miyagi 37400 S. Hatusima & Y. Iriomote-jima in the southern Ryukyus. Some taxonomists treat the Ryukyu plants as F. tashiro- ana Ohwi being endemic to Japan (Ohwi, 1931). personal no. , herbarium of voucher specimen) Therefore, further study is required to investigate

Locality ( the endemism of the plants from Japan including Iriomote-jima.

Eriocaulon truncatum Buch.-Ham. ex Mart. Y. Miyagi & E. Nakata 35809 , RYU14685) ( S. Hatusima , Y. Miyagi & E. Nakata 35517 , RYU15847) ( S. Hatusima , Y. Southern Ryukyus, Yaeyama Islands, Yonaguni-jima. Islands, Yonaguni-jima. Yaeyama Southern Ryukyus, Islands, Yonaguni-jima. Yaeyama Southern Ryukyus, Southern Ryukyus, Miyako Islands, Tarama-jima. ( Tarama-jima. Miyako Islands, Southern Ryukyus, Y. Jotani & S. Masuda s.n. , TNS825502) ( Y. Tokuno-shima. Amami Islands, Central Ryukyus, Y. Jotani & S. Masuda s.n. , TNS825515) ( Y. Tokuno-shima. Amami Islands, Central Ryukyus, Central Ryukyus, Okinawa Islands, Iheya-jima, Mt. Kayo-san. ( Central Ryukyus, Southern Ryukyus, Yaeyama Islands, Kohama-jima. ( Yaeyama Southern Ryukyus, Southern Ryukyus, Miyako Islands, Miyako-jima. ( Southern Ryukyus, Central Ryukyus, Okinawa Islands, Ie-jima. ( Central Ryukyus, (Eriocaulaceae; RL2019: CR; Fig. 3B) * This helophyte grass was previously reported status RL2019 NT from Tokuno-shima, Okinawa-jima, Kume-jima in the central Ryukyus, Ishigaki-jima, Iriomote-

Table. 1. Table. Continued. jima and Yonaguni-jima in the southern Ryukyus (Tateishi et al., 2018a); and from Taiwan, China, Indochina, the Philippines and Thailand Japanese common name Hana-shinbogi Iwa-zansho Aridoshi Boroboronoki Bochoji Aragata-sankirai Tachibana (Miyamoto, 2015). Although several populations occur in the northern and central parts of Oki- nawa-jima, the majority of populations have been destroyed by anthropogenic development (Tateishi et al., 2018a). A few populations are known from Ishigaki-jima and Iriomote-jima, but the present status of populations occurring on other islands is unclear (Tateishi et al., 2018a). Species We recorded a first occurrence of E. truncatum K.Koch from Dana, Iheya-jima in the central Ryukyus. (Willd.) Lindl. (Willd.)

(Merr.) T.Koyama verruculosa (Merr.) C.Presl var. The locality includes a wetland habitat, and (Makino) Tanaka many helophyte species have been reported from this area (Niiro and Shinzato, 1978). However, these wetlands are threatened by ongoing devel- Glycosmis citrifolia Zanthoxylum beecheyanum Gaertn.f. var. indicus Damnacanthus indicus Gaertn.f. var. Schoepfia jasminodora Siebold et Zucc. (Lour.) Poir. Psychotria rubra (Lour.) Smilax bracteata Citrus tachibana opment and the spread of naturalized plant spe- cies. Some taxonomists treat the Ryukyu plants

Family as Eriocaulon nigrum Lecomte var. suishaense Rubiaceae Schoepfiaceae Smilacaceae Rutaceae (Hayata) Hatusima et T.Koyama distributed in 82 Goro Kokubugata et al. the Ryukyus, Taiwan, China and Indochina (e.g., surveys on Kikai-jima conducted in 2009 (details Hatusima, 1975; Walker, 1976; Tateishi et al., not shown). Some taxonomists treat the Ryukyus 2018a). Therefore, further studies are required to plants as T. concolor var. formosana Yamazaki understand the taxonomy of the plants from the distributing in only the Ryukyus and Taiwan Ryukyus and in particular from Iheya-jima. (Tateishi et al., 2018b). Therefore, comparative surveys including plants from Southeast Asia, Enhalus acoroides (L.f.) Rich. ex Steud. India and Sri Lanka are necessary to understand (Hydrocharitaceae; RL2019: VU; Fig. 3C) its taxonomic status. This submerged growing seagrass has been reported from Ishigaki-jima, Iriomote-jima and Pericampylus formosanus Diels (Menisperma- Yonaguni-jima in the Yaeyama Islands; and is ceae; RL2019:CR; Fig. 4A) widely distributed from Indochina to Australia This perennial vine was previously reported and Africa (Yokota and Yasuda, 2018). Some from only Miyako-jima in the southern Ryukyus; populations of this species are known from Ishi- and from Taiwan and southern part of China gaki-jima and Iriomote-jima, while the present (Hatusima, 1975), but the present status of this status of population in Yonaguni-jima is not clear species on the Miyako population is unclear (Yokota and Yasuda, 2018). (Shinjo and Kawakami, 2018). We report a new locality from Kohama-jima in We report a new record of this species from the Yaeyama Islands. Kohama-jima is situated Ishigaki-jima, which is the second record from between Ishigaki-jima and Iriomote-jima, and Japan at island level. treated as one of the Sekisei Lagoon Islets with other eight islets (Chinen, 1993). Given this find- Nymphoides coreana (H.Lév.) H.Hara (Menyantha- ing, we suspect that this species may occur on ceae; RL2019: VU; Fig. 4B) other islets in the Sekisei Lagoon Islets too. This floating aquatic has been reported from Miyako-jima, Ishigaki-jima, Iriomote-jima, Torenia concolor Lindl. (Linderniaceae; Kayama-jima, and Yonaguni-jima in the southern RL2019: EN; Fig. 3D) Ryukyus; from Honshu, Shikoku, and Kyushu of This trailing perennial herb was previously Japan, Korea and China (Tateishi et al., 2018c). reported from Amami-ohshima, Uke-jima, Oki- The present status of populations in Miyako-jima nawa-jima in the central Ryukyus, and Miyako- are not clear, while some populations of this spe- jima in the southern Ryukyus; and from Taiwan, cies are known from the reminder islands (Tatei- China, Southeast Asia, India and Sri Lanka shi et al., 2018c). (Ohashi, 2017). We confirmed that several popu- We report a new locality for this species on lations persist on Amami-ohshima by our recent Irabu-jima, which is the second recorded occur- field survey conducted in 2019, but we could not rence from the Miyako Islands. confirm the population on Kikai-jima in our field survey conducted in 2017 (details not shown). It Jasminum superfluum Koidz. (Oleaceae; is likely that the populations on Okinawa-jima RL2019: VU; Fig. 4C) and Miyako-jima in the Ryukyus have become This woody vine has been reported from extinct (Tateishi et al., 2018b). Kikai-jima, Yoron-jima, Okinawa-jima in the We report a new record of this species from central Ryukyus, Miyako-jima, Irabu-jima, and Kikai-jima, which is the third record from the Ishigaki-jima in the southern Ryukyus; and from Amami Islands in the central Ryukyus. However, Taiwan (Hatusima, 1971). This species was also this species may have come from a population found from Sesoko-jima of the central Ryukyus that is now extirpated, as we did not find any (Shimabuku, 1973). other plant of this species during our detailed We report a locality from Iheya-jima being an New Localities of Plants from the Ryukyus 83

Fig. 2. Voucher specimen for new record at island level in the subtropical Ryukyus. A. Deeringia polysperma (Amaranthaceae; RYU). B. Rhus javanica var. javanica (Anacardiaceae; RYU). C. Conyza leucantha (Astera- ceae; RYU). D. Cordia aspera subsp. kanehirae (Boraginaceae; RYU). Scale bars = 3 cm. 84 Goro Kokubugata et al.

Fig. 3. Voucher specimen for new record at island level in the subtropical Ryukyus. A. Fimbristylis tashiroana (Cyperaceae; TNS). B. Eriocaulon truncatum (Eriocaulaceae; URO). C. Enhalus acoroides (Hydrocharita- ceae; RYU). D. Torenia concolor (Linderniaceae; RYU). Scale bars = 3 cm. New Localities of Plants from the Ryukyus 85

Fig. 4. Voucher specimen for new record at island level in the subtropical Ryukyus. A. Pericampylus formosanus (Menispermaceae; TNS). B. Nymphoides coreana （Menyanthaceae; RYU). C. Jasminum superfluum (Ole- aceae; RYU). D. Ludwigia adscendens (Onagraceae). Scale bars = 3 cm. 86 Goro Kokubugata et al. islet adjacent to Okinawa-jima, which is the third Naha (in Japanese). Hatusima, S. and Amano, T. 1994. Flora of the Ryukyus, occurrence from the Okinawa Islands. Taxonom- Southern of Amami Islands, 2nd ed. The Biological ically, Hatusima (1975) treated the Ryukyus Society of Okinawa, Nishihara (in Japanese). plants as J. sinensis Hemsl. distributed in the Japanese Ministry of Environment. 2019. Red list 2019, Ryukyus and southern part of China. Thus, fur- Vascular Plants, 4th ed. https://www.env.go.jp/nature/ ther taxonomic studies based on the plants from kisho/hozen/redlist/index.html (in Japanese). the Ryukyu, Taiwan and China are required. Kokubugata, G., Yokota, M. and Kato, M. 2010. Note on the taxonomy, biogeography and conservation of endangered plant species in the Ryukyus. Korean Jour- Ludwigia adscendens (L.) H.Hara (Onagraceae; nal of Plant Taxonomy 40: 193–201. RL2019: VU; Fig. 4D) Miyamoto, F. 2015. Eriocaulaceae. In: Ohashi, H., This hydrophyte herbaceous species has been Kadota, Y., Murata, J., Yonekura, K. and Kihara, H. reported from Okinawa-jima in the central (eds.), Wild Flowers of Japan vol. 1, pp. 281–286. Hei- bonsha, Tokyo (in Japanese). Ryukyus, the Daito Islands, the Miyako Islands, Miyawaki, A. 1977. Nature and plants in Japan. In: Miy- and Ishigaki-jima in the southern Ryukyus; and awaki, A. (ed.), Flora of Japan, pp. 1–32. Gakken, is widely distributed in Taiwan and tropical areas Tokyo (in Japanese). of Asia (Hatusima, 1975). Populations on the Niiro, Y. and Shinzato, K. 1978. Vegetation of lheya-Izena Miyako Islands have declined because of anthro- Shoto. Bulletin of Science and Engineering Division, University of Ryukyus, Mathematics & Natural Sci- pogenic activities, and only one population is ences 3: 81–105 (in Japanese with English abstract). known from Ishigaki-jima in the Yaeyama Ohashi, 2017. Linderniaceae. In: Ohashi, H., Kadota, Y., Islands (Yokota et al., 2018b). Murata, J., Yonekura, K. and Kihara, H. (eds.), Wild We report a new locality of this species on Flowers of Japan vol. 5, pp. 96–100. Heibonsha, Tokyo Kohama-Jima, which is the second record for the (in Japanese). Yaeyama Islands. Given this finding on Kohama- Ohwi, J. 1931. Symbolae ad Floram Asiae Orientalis III. Botanical Magazine, Tokyo 45: 377–389. jima, we suspect that this species may also occur Ryukyu Plant Research Group. 2018 onward. Database of on other islets in the Sekisei Lagoon Islets. Ryukyu Plants. https://www.kahaku.go.jp/research/ activities/project/hotspot_japan/ryukyus/db/ National Museum of Nature and Science, Tsukuba (in Japanese). Acknowledgments Saito, Y., Akai, K., Amano, M. and Tateishi, Y. 2019. Notes on the distribution of vascular plants: new “ This study was supported by a project of Bio- records from Kumejima Island, the . logical Properties of Biodiversity Hotspots in Biological Magazine Okinawa 57: 253–258 (in Japa- Japan” conducted by the National Museum of nese with English abstract). Nature and Science, Tokyo. Shimabuku, K. 1973. Flora of , Okinawa. Ryukyu University Sesoko Marine Science Laboratory Technical Report 2: 1–13 (in Japanese). References Shimabuku, K. 1997. Check List Vascular Flora of the Ryukyu Islands. Kyushu University Press, Fukuoka (in Abe, A., Nakasone, T. and Kokubugata, G. 2016. Note- Japanese). worthy collection records of Lipocarpha microcephala Shinjo, K. and Kawakami, I. 2018. Pericampylus formo- (Cyperaceae) and Polygala chinensis (Polygalaceae) sanus Diels. In: Okinawa Prefectural Government from of the Ryukyus, Japan. Bulletin of (ed.), Threatened Wildlife in Okinawa, 3rd ed. (Fungi the National Museum of Nature and Science, Series B and Plants). Okinawa Prefectural Government, Naha, p. (Botany) 42: 73–76. 437 (in Japanese). Chinen, M. 1993. Flora of the Sekisei Lagoon Islets, the Tagawa, H. and Miyagi, Y. 1991. Vegetation of the south- Yaeyama Islands. Biological Magazine Okinawa 11: west islands and its features and conservation. In: 75–100 (in Japanese). Nature Conservation Bureau, Environmental Agency of Hatusima, S. 1971. Flora of the Ryukyus. Okinawa Asso- Japan (ed.), Report on Essential Conditions for Conser- ciation of Biology Education, Naha (in Japanese). vation of Wild Species in Southwest Islands in Fiscal Hatusima, S. 1975. Flora of the Ryukyus, added and cor- 1990, pp. 122–183. WWF Japan, Tokyo (in Japanese). rected ed. Okinawa Association of Biology Education, Tateishi, Y. and Iha, Z. 2018. Rhus javanica L. var. javan- New Localities of Plants from the Ryukyus 87

ica. In: Okinawa Prefectural Government (ed.), Threat- Yokota, M. and Nakata, N. 2018. Fimbristylis dichotoma ened Wildlife in Okinawa, 3rd ed. (Fungi and Plants). (L.) Vahl subsp. podocarpa (Nees et Meyen) T. Okinawa Prefectural Government, Naha, p. 440 (in Koyama. In: Okinawa Prefectural Government (ed.), Japanese). Threatened Wildlife in Okinawa, 3rd ed. (Fungi and Tateishi, Y., Ikehara, N., Yasuda, K. and Yokota, M. Plants). Okinawa Prefectural Government, Naha, pp. 2018a. Eriocaulon nigrum Lecomte var. suishaense 359–360 (in Japanese). (Hayata) Hatusima et T. Koyama. In: Okinawa Prefec- Yokota, M. and Yasuda, K. 2018. Enhalus acoroides (L.f.) tural Government (ed.), Threatened Wildlife in Oki- Rich. ex Steud. In: Okinawa Prefectural Government nawa, 3rd ed. (Fungi and Plants). Okinawa Prefectural (ed.), Threatened Wildlife in Okinawa, 3rd ed. (Fungi Government, Naha, p. 326 (in Japanese). and Plants). Okinawa Prefectural Government, Naha, Tateishi, Y. Ikehara, N. and Yokota, M. 2018b. Torenia pp. 298–299 (in Japanese). concolor Lindl. var. formosana Yamazaki. Okinawa Yokota, M., Shinjo, K. and Higa, S. 1997. Notes on the Prefectural Government (ed.), Threatened Wildlife in distribution of plants in the Ryukyus 14. Biological Okinawa, 3rd ed. (Fungi and Plants). In: Okinawa Pre- Magazine Okinawa 35: 49–54 (in Japanese). fectural Government, Naha, p. 276 (in Japanese). Yokota, M., Kawakami, I., Kitahara, T., Abe, A., Sato, N. Tateishi, Y., Kitahara, T. and Yokota, M. 2018c. Nymphoi- and Kashima, M. 2018a. Deeringia polysperma des coreana (H.Lév.) H.Hara. In: Okinawa Prefectural (Roxb.) Moq. In: Okinawa Prefectural Government Government (ed.), Threatened Wildlife in Okinawa, 3rd (ed.), Threatened Wildlife in Okinawa, 3rd ed. (Fungi ed. (Fungi and Plants). Okinawa Prefectural Govern- and Plants). Okinawa Prefectural Government, Naha, p. ment, Naha, p. 245 (in Japanese). 158 (in Japanese). Walker, E. H., 1976. Flora of Okinawa and the Southern Yokota, M., Tomiyama, H., Kitahara, T., Abe, A., Ryukyu Islands. Smithsonian Institute Press, Washing- Nakasone, T., Sato, N. and Shiroma, M. 2018b. Lud- ton, D.C. wigia adscendens (L.) H.Hara (Onagraceae). In: Oki- Yokota, M. 1997. Small plants in Okinawa. In: Ikehara, S. nawa Prefectural Government (ed.), Threatened Wild- and Katoh, Y. (eds.), Knowing Nature of Okinawa, pp. life in Okinawa, 3rd ed. (Fungi and Plants). Okinawa 139–155. Tsukiji Shokan, Tokyo (in Japanese). Prefectural Government, Naha, pp. 224–225 (in Japa- Yokota, M. and Ikehara, E. 2018. Conyza leucantha (D. nese). Don) Ludlow et Raven. In: Okinawa Prefectural Gov- Yonekura, K. 2017 Boraginaceae. In: Ohashi, H., Kadota, ernment (ed.), Threatened Wildlife in Okinawa, 3rd ed. Y., Murata, J., Yonekura, K. and Kihara, H. (eds.), Wild (Fungi and Plants). Okinawa Prefectural Government, Flowers of Japan vol. 5, pp. 47–58. Heibonsha, Tokyo Naha, p. 291 (in Japanese). (in Japanese).