J. Jpn. Bot. 92(4): 177–183 (2017)

Systematic Studies of Parasenecio (Asteraceae-Senecioneae) II. Parasenecio sadoensis, a New Species from Sado Island, Central Honshu, Japan

a, b Yuichi Kadota * and Norihito Miura

aDepartment of Botany, National Museum of Nature and Science, 4-1-1, Amakubo, Tsukuba, 305-0005 JAPAN; bHoshizaki Institute for Wildlife Protection, Hoshizaki Green Foundation, Shinji-ko Lake Green Park, 1664-2, Sono-cho, Idzumo, 691-0076 JAPAN *Corresponding author: [email protected]

(Accepted on March 4, 2017)

A new species of Parasenecio (Asteraceae-Senecioneae), P. sadoensis Kadota, is described. Parasenecio sadoensis is different from P. adenostyloides (Franch. & Sav. ex Maxim.) H. Koyama by having thicker and robust, horizontal rhizome, fragile stems and petioles easy to break, flowering in July, usually smaller, spike-like raceme, 5–6 florets per head, 5 involucral phyllaries, shorter milky white corollae tinged pale blue, purplish blue anthers and shorter pappi. Parasenecio sadoensis is restricted to Sado Island and was found to grow under Fagus crenata woods. Parasenecio adenostyloides is not known from Sado Island. (Continued from J. Jpn. Bot. 90: 92–97, 2015).

Key words: Asteraceae, Japan, new species, Parasenecio adenostyloides, Parasenecio amagiensis, Parasenecio sadoensis, Sado Island.

This is part of systematic studies of the genus to Parasenecio adenostyloides (Franch. & Sav. Parasenecio (Asteraceae-Senecioneae) (Kadota ex Maxim.) H. Koyama but are different from 2005, 2009, 2015). the latter in the number of involucral phyllaries In early October 2015 I visited Sado Island, (5 vs. 3), the shape of synflorescence (usually Niigata Prefecture, central Honshu, Japan spike-like racemose vs. paniculate) and the to examine Cirsium and Saussurea plants shape of leaf blades (reniform vs. pentagonal- (Asteraceae-Cynareae). At that time I had an reniform). According to Ms. Yōko Watanabe opportunity to observe curious Parasenecio the plants at issue may flower in July. Therefore plants on the island. Plants resembling they are an early bloomer since montane species Parasenecio hastatus L. subsp. orientalis of Japanese Parasenecio begin to flower in late (Kitam.) H. Koyama var. ramosus (Maxim.) H. August at the earliest. I collected a few rhizomes Koyama (= Cacalia hastata L. subsp. orientalis and raised them at Wako, Saitama Prefecture, Kitam. var. ramosa (Maxim.) Kitam.) occurred central Japan. In early spring 2016 the plants commonly throughout Sado Island. The plants in cultivation began to sprout. The leaves were in question, however, already withered while the membranous, soft but somewhat fleshy and P. hastatus subsp. orientalis var. ramosus-like vaguely lustrous. plants were in full bloom. The plants are similar In late July 2016 field survey was done at

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Fig. 1. Type of Parasenecio sadoensis Kadota from Sado Island, Niigata Pref., central Japan (Y. Kadota 1602003, TNS01270087, holotype). August 2017 The Journal of Japanese Botany Vol. 92 No. 4 179 Kadota from Sado Island, Niigata Pref., central Japan. A. Habit in the fruiting time. B. Part of synflorescence showing proximally proximally showing synflorescence of Part B. time. fruiting the in Habit A. Japan. central Pref., Niigata Island, Sado from Kadota sadoensis

Parasenecio pale bluish corollae. Courtesy of Ms. Yōko Watanabe. C. Leaf sheath. D. Rhizome. A, C–D. On 27 July 2016. B. On 12 July 2016. July 12 On B. 2016. July 27 On C–D. A, Rhizome. D. sheath. Leaf C. Watanabe. Yōko Ms. of Courtesy corollae. bluish pale Fig. 2. 2. Fig. 180 植物研究雑誌 第 92 巻 第 4 号 2017 年 8 月 the locality in Sado Island. As a result it was shi [Sado Island], 27 July 2016, Y. Kadota clear that the plants were characterized by milky 1602003 (TNS01270087–holotype; Fig. 1). white corollae with pale bluish lobes, purplish A medium-sized, perennial, 30–70 cm tall. blue anthers, thicker horizontal rhizome and Rootstock robust, 1–2 cm in diameter, running incomplete (semi-opened) leaf-sheaths. The horizontally, with a few to several scapes at the petioles enclosed the stem and became leaf- nodes and with thread-like roots. Stem suberect, sheaths but the leaf-sheaths did not surround simple, ribbed, green tinged purple, 3–6 mm the stem completely. In this way the plants in in diameter at base. Basal leaves withered at question superficially resembled P. amagiensis anthesis. Cauline leaves 3–4. Lower cauline (Kitam.) H. Koyama (Kitamura 1938, 1942, leaves membranous, soft and slightly fleshy, dull 1957, 1981, Koyama 1962, 1967, 1969, 1995). lustrous on the adaxial side; blades reniform, Additional field examination was also executed 12–16 cm long, 21–23 cm wide, palmately to observe P. amagiensis in Mt. Tōgasa-yama, veined, coarsely dentate, glabrous on both sides, Izu Peninsula, Shizuoka Prefecture, central deeply cordate at base; petioles 10–14 cm long, Honshu, Japan in October 2016. As a result glabrous, minutely auriculate, vaginate at base. of this examination it was confirmed that P. Upper cauline leaf triangular-cordate, 4–5 cm amagiensis was distinguished from the plants long, 5–6 cm wide, finely serrate, cuspidate at in question by having completely enclosed leaf- apex, cuneate to cordate at base, sessile. Flowers sheaths, slender horizontal rhizome, scabrous in July. Synflorescence spike-like racemose, leaves, paniculate synflorescence and ascending simple or sometimes branched in its lowest heads. Consequently it is clarified that the part, capitula ca. 10 per raceme, horizontal to plants represent an undescribed species. This is nodding; peduncles 1–5 mm long, glabrous, described here as a new species, Parasenecio with linear bracts 1–2 mm long. Involucres sadoensis Kadota. narrowly cylindrical, 8–9 mm long, 2–3 mm in diameter, glabrous; phyllaries 5 in a row, Taxonomic treatment herbaceous, 7 mm long, 1.5 mm wide, narrowly Parasenecio W. W. Sm. & J. Small. ovato-lanceolate, acuminate at apex; florets 5–6 Sect. Koyamacalia (H. Robins. & Brettel) Y. per capitulum. Corollae milky white tinged pale L. Chen. blue, 5–7 mm long; lobes 1 mm long; throats Parasenecio sadoensis Kadota, sp. nov. 1.5–2.5 mm long; tubes 2.5–3.5 mm long, longer [Figs. 1, 2] than the throats. Anthers 3 mm long, purplish Parasenecio sadoensis Kadota is similar to P. blue. Achenes cylindrical, 4 mm long, 0.3 mm in adenostyloides (Franch. & Sav. ex Maxim.) H. diameter, glabrous, faintly striate; pappi white, Koyama in having rhizome running horizontally 4–5 mm long. and dull lustrous soft leaves, however, the former Chromosome number: 2n = 120 (Fig. 3). is distinguished from the latter by having 1) Japanese name: Sado-kani-kōmori (nom. thicker and robust rhizome (Fig. 2D), 2) fragile nov.). stems and petioles easy to break, 3) flowering 新和名：サドカニコウモリ． in July, 4) smaller, spike-like raceme or raceme Additional specimens examined: JAPAN. Honshu. 1–2 times branched in the proximal part, 5) 5–6 Niigata Pref., Sado-shi [Sado Island], 5 Oct. 2015, Y. Kadota 159001 (TNS); Sado-shi [Sado Island], 27 florets per head, 6) 5 involucral phyllaries, 7) July 2016, Y. Kadota 1602001, 1602002, 1602004 shorter, milky white corollae tinged pale blue (TNS01270086, 01270090, 01270091). (Fig. 2B), 8) purplish blue anthers, and 9) shorter Note: The somatic chromosome number pappi. 2n = 120 of Parasenecio sadoensis shows Type: JAPAN. Honshu. Niigata Pref., Sado- an infrequent number in Parasenecio sect. August 2017 The Journal of Japanese Botany Vol. 92 No. 4 181

Fig. 3. Somatic chromosomes (2n = 120) of Parasenecio sadoensis Kadota (Sado Island, Niigata Pref., Honshu, Japan). Scale: 5 µm.

Koyamacalia. However, similar chromosome 1981, Koyama 1962, 1967, 1969, 1995) but numbers were reported also in P. kamtschaticus has not been known from Sado Island where P. (Maxim.) Kadota from Hokkaido and Honshu, sadoensis exclusively occurs. Japan [2n = 120, Koyama (1966, 1995) and Nishikawa (1982); 2n = 118, Nishikawa (1980)]. I wish to show my cordial thanks to In P. amagiensis (sect. Taimingasa (Kitam.) Ms. Yōko Watanabe, Sado-shi, Mr. Seitarō H. Koyama) the petioles completely enclose Nakagawa, Sado-shi and Mr. Hiromitsu stem at base and the petiole bases form leaf- Yanagita, Odziya-shi, for their kind help in my sheaths (Fig. 4B). In P. sadoensis the petioles field examination of Parasenecio sadoensis also do enclose stem but both ends of the in Sado Island, Niigata Prefecture, central petioles become small auricles and the leaf- Japan; to Mr. Yasushi Sato, Ito-shi and Ms. sheaths do not enclose the stem completely Hiroko Nakayama, Kamakura-shi for their kind (Figs. 2C, 4A). This situation is similar to that in guidance to the locality of P. amagiensis, Mt. P. adenostyloides (Koyama 1962). In the case of Tōgasa-yama, Ito-shi, Shizuoka Prefecture, P. chokaiensis (Kudō) Kadota, another member central Honshu, Japan. of sect. Koyamacalia, the petiole bases surround the stem, and both ends of the petiole bases Literature cited become auriculate but leaf-sheath is not formed Kadota Y. 2005. A new species of Parasenecio (Fig. 4C). (Asteraceae), P. ogamontanus, from Akita Prefecture, northern Japan. J. Jpn. Bot. 80: 214–220. Parasenecio adenostyloides is an endemic Kadota Y. 2009. A new species of Parasenecio of Japan and is relatively widely distributed in (Asteraceae), P. hosoianus, from Aomori Prefecture, Honshu and Shikoku (Kitamura 1938, 1939, northern Japan. J. Jpn. Bot. 84: 1–7. 182 植物研究雑誌 第 92 巻 第 4 号 2017 年 8 月

Fig. 4. Comparison of petiole bases among Parasenecio sadoensis Kadota (A), P. amagiensis (Kitam.) H. Koyama (B) and P. chokaiensis (Kudō) Kadota (C). A. Sado Island, Niigata Pref., on 27 July 2016. B. Mt. Tōgasa-yama, Shizuoka Pref., on 3 Oct. 2016. C. Mt. Chōkai-san, Yamagata Pref., on 17 Sept. 2012.

Kadota Y. 2015. Systematic studies of Parasenecio Koyama H. 1966. Cytological studies of Compositae 2. (Asteraceae-Senecioneae) I. Parasenecio katoanus, Cacalia auriculata var. kamtschatica. Acta Phytotax. a new species from Yamagata Prefecture, northern Geobot. 22: 11–14. Honshu, Japan. J. Jpn. Bot. 90: 92–97. Koyama H. 1967. Taxonomic studies on the tribe Kitamura S. 1938. Les Cacalia du Japan. Acta Phytotax. Senecioneae of Eastern Asia. I. General part. Mem. Geobot. 7: 236–251 (in Japanese). Fac. Sci., Kyoto Univ., Ser. Biol. 33: 181–209. Kitamura S. 1942. Cacalia L. Mem. Coll. Sci. Kyoto Koyama H. 1969. Taxonomic studies on the tribe Imper. Univ., Ser. B 16: [Compos. Jap. 3] 202–226. Senecioneae of Eastern Asia. II. Enumeration of the Kitamura S. 1957. Cacalia L. In: Kitamura S., Murata G. species of Eastern Asia. Mem. Fac. Sci., Kyoto Univ., and Hori M., Coloured Illustrations of Herbaceous Ser. Biol. 35: 137–183. Plants of Japan. Sympetalae. 1: 46–49, pls. 15–16. Koyama H. 1995. Parasenecio W. W. Sm. & J. Small. In: Hoikusha Publishing Co., Osaka (in Japanese). Iwatsuki K., Boufford D. E. and Ohba H. (eds.), Flora Kitamura S. 1981. Cacalia L. In: Satake Y., Ohwi J., of Japan 3b: 47–53. Kodansha Ltd., Tokyo. Kitamura S., Watari S. and Tominari T. (eds.), Wild Nishikawa T. 1980. Chromosome counts of flowering Flowers of Japan. Herbaceous Plants (Including Dwarf plants of Hokkaido (3). J. Hokkaido Univ. Educ., Sect. Subshrubs). 3: 178–181, pls. 149–153. Heibonsha, 2B, 31: 19–23. Tokyo (in Japanese). Nishikawa T. 1982. Chromosome counts of flowering Koyama H. 1962. On the section Taimingasa of the genus plants of Hokkaido (6). Rep. Taisetsuzan Inst. Sci. (17): Cacalia. Acta Phytotax. Geobot. 20: 172–175 (in 9–16. Japanese). August 2017 The Journal of Japanese Botany Vol. 92 No. 4 183

a b 門田裕一 ，三浦憲人 ：コウモリソウ属（キク科キオン連） の分類学的研究 II．佐渡島産の 1 新種，サドカニコウ モリ 佐渡島からコウモリソウ属コウモリソウ節（キク科） るが，葉柄の基部はわずかに耳状に拡がり，葉鞘は完全 Parasenecio W. W. Sm. & J. Small sect. Koyamacalia (H. には閉じない．葉柄の基部が抱茎するが完全には閉じな Robins. & Brettel) (Asteraceae-Senecioneae) の 1 新種， い点では，サドカニコウモリはカニコウモリと同様であ サドカニコウモリ Parasenecio sadoensis Kadota を記載 る．サドカニコウモリの染色体数 2n = 120 は，コウモ した．この新種は地下茎が横走し，葉が軟質で鈍い光 リソウ節のほとんどの種が 2n = 60 であることを踏まえ 沢がある点でカニコウモリ P. adenostyloides (Franch. & ると，特異な数ということができる．しかし，染色体 Sav. ex Maxim.) H. Koyama に似ているが，以下の点で 数 2n = 118 と 2n = 120 はミミコウモリ P. kamtschaticus 明瞭に異なる．①地下茎はより太くかつ頑丈で，②植物 (Maxim.) Kadota でも報告されている． 体が軟らかく，茎や葉柄が折れやすく，③ 7 月に開花 サドカニコウモリはブナ林の林床に生える．個体数が し，④花序がより小型で，穂状または基部でのみ分枝 極めて少ないため，保護の目的で産地の詳細は省略し する総状になり，⑤花冠は長さ 5–7 mm，乳白色で青み た．なお，カニコウモリそのものは佐渡島には知られて を帯び，⑥小花が頭花当たり 5–6 個あり，⑦総苞片は 5 いない． 個で，⑧葯が青紫，⑨冠毛が長さ 4–5 mm と短い点で明 （a国立科学博物館植物研究部， 瞭に異っている．葉柄の基部が葉鞘状になる点ではイ bホシザキ野生生物研究所） ズカニコウモリ P. amagiensis (Kitam.) H. Koyama に似