Bot. Bull. Acad. Sin. (2002) 43: 155-159

Chung and Peng — Senecio kuanshanensis (Asteraceae)

Senecio kuanshanensis (Asteraceae), a new species from southern Taiwan

Shih-Wen Chung¹ and Ching-I Peng^2,*

¹Division of Forest Biology, Taiwan Forestry Research Institute, 53 Nanhai Road, Taipei 100, Taiwan

²Institute of Botany, Academic Sinica, Nankang, Taipei 115, Taiwan

(Received June 15, 2001; Accepted February 25, 2002)

Abstract. A new species of Asteraceae from Taiwan, Senecio kuanshanensis C.-I Peng & S.W. Chung, a distinct member of sect. Crociseris (Reichenb.) Hall. & Wohlf. ser. Nemorenses Gagnidze, is described and illustrated. Senecio kuanshanensis is apparently rare, presently known only from mountain ridges of Kuanshan, at (2,500-)3,000-3,300 m elevation in the southern part of the Central Mountain Range of Taiwan. In habit the new species somewhat resembles S. morrisonensis Hayata, an endemic congener from Taiwan, but it is clearly distinct in having longer peduncles (3-7 cm vs. 0.5-2[-3] cm), longer involucres (8-10 mm vs. 4.5-6 mm), longer corolla tube in the disc florets (4-5 mm vs. 3-3.5 mm), longer rays (9-14 mm vs. 5.5-7.2 mm) in the ray florets, and median cauline leaves that are deeply bipinnatipartite to tripinnatipartite (vs. serrate to coarsely dentate or deeply pinnately lobed).

Keywords: Asteraceae; Compositae; New species; Rare species; Senecio kuanshanensis; Senecioneae; Taiwan; Taxonomy.

Senecio is a cosmopolitan genus of ca. 1,250-3,000 species, depending on circumscription (Diggs et al., 1999). New information and new taxonomic concepts indicate that the genus should be divided into various segregates (Barkley et al., 1996). Based on the generic concepts adopted in recent taxonomic studies on the tribe Senecioneae of eastern Asia (Jeffrey and Chen, 1984; Chen, 1999), seven species and one additional variety of Senecio were recognized in the recently revised Flora of Taiwan (Peng and Chung, 1998). With the exception of S. vulgaris L., which is naturalized around villages at 2,000-2,500 m in Taiwan, all members of the genus are indigenous and five are endemic.

Subsequent to our recent description of a new species of Senecio from eastern Taiwan, S. tarokoensis C.-I Peng (Peng and Leu, 1999), another unique species was discovered on Kuanshan at ca. 3,000-3,300 m in the southern part of the Central Mountain Range. It is not referable to any species heretofore known in eastern Asia (Koyama, 1968, 1969; Jeffrey and Chen, 1984; Iwatsuki et al., 1995; Peng et al., 1998; Peng and Leu, 1999; Chen, 1999) and is here described as new.

Senecio kuanshanensis C.-I Peng & S.W. Chung, sp. nov.—TYPE: TAIWAN. Kaohsiung Hsien, Taoyuan Hsiang, Yushan National Park, from `3026 Lodge' to Kuanshan, 120° 54' 22" E, 23° 14' 45" N, elev. ca. 3,300

m, in Abies forest on mountain ridges, frequent on forest floor, at peak anthesis, 20 Aug 1998, Kuo-Fang Chung 1022, accompanied by Yoko Kita, Chien-Chih Chen, and S. J. Moore (holotype: HAST; isotypes: E, GH, K, KUN, MO, NCUF, PE, TAIF, TNM).

Ãö¤s¤d¨½¥ú Figures 1-3

Haec species Senecioni morrisonensi Hayata subsimilis, sed ab eo foliis caulinis medianis profunde bipinnatipartitis usque tripinnatipartitis (vs. irregulariter pinnatifidis vel -partitis), pedunculo 3-7 (vs. 0.5-2[-3]) cm longo, involucro 8-10 (vs. 4.5-6) mm longo atque partibus floralibus majoribus inter eas flosculorum radii limbo 9-14 (vs. 5.5-7.2) mm longo, eorum disci tubo angusto 4-5 (vs. 3-3.5) mm longo manifeste distinguitur. 

Erect, perennial rhizomatous herb. Stem 32-44 cm tall, usually simple basally, branched above, glabrous. Basal and lower cauline leaves withered at anthesis; middle and upper cauline leaves many, base attenuate into petiole, 1-2 cm long, glabrous on both surfaces, ovate, 11-13 cm long, 3-5.5 cm wide, deeply bipinnatipartite to tripinnatipartite, irregularly incised, segments spreading, lanceolate to narrowly oblong or linear, papery; upper cauline leaves gradually smaller, linear-lanceolate to linear, remotely dentate, subsessile. Heads radiate, many terminal on branches, forming a corymb; peduncles 3-7 cm long, slender, nearly glabrous to sparingly puberulous, with 1-3 linear bracteoles; bracteoles 2-3 mm long, subglabrous or sparsely pubescent. Involucre subcylindric, ca. 8-10 mm long, 4-6 mm across, calyculate; bracts 2-seriate, ca. 13, herbaceous, linear, 0.5 -1 mm wide, with narrow scarious margins, apex acute to subobtuse, puberulous, otherwise

*Corresponding author. Tel: 886-2-2789-9590 ext 404; Fax: 886-2-2789-1623; E-mail: bopeng@gate.sinica.edu.tw

Botanical Bulletin of Academia Sinica, Vol. 43, 2002

Figure 1. Senecio kuanshanensis C.-I Peng & S.W. Chung. A, Habit; B, Apical portion of a leaf; C, D. Capitulum; E, Bracteole; F, Involucral bract, abaxial surface; G, Apex of involucral bract, much magnified; H, Involucral bract, adaxial surface; I, Ray floret; J, Portion of ray floret; K, Style branches; L, Disc floret; M, Disc floret, achene and pappus removed; N, Stamens, expanded; O, Achene; P, Q. Pappus; R, Achene, pappus removed. (All from S. W. Chung 101, HAST)

Chung and Peng — Senecio kuanshanensis (Asteraceae)

Figure 2. Senecio kuanshanensis, showing habit and habitat.

Figure 3. Senecio kuanshanensis, upper part of a plant, showing leaves and capitula.

Distribution and notes. Endemic and apparently rare in Taiwan; presently known only along semishaded trails in Tsuga-Abies forests and in Yushania bamboo grasslands near the mountain ridge of Kuanshan, at (2,500-)3,000- 3,300 m elevation (Figure 4). Mt. Kuanshan and its neighboring area are noted for harboring a number of endemic and/or rare species of Asteraceae, e.g. Senecio taitungensis S. S. Ying (endemic; Ying, 1990), Saussurea kanzanensis Kitam. (endemic and vulnerable; Peng, 2000), Parasenecio monantha (Diels) C.-I Peng & S.W. Chung (rare and vulnerable; Peng, 2000) and Parasenecio nokoensis (Masam. & Suzuki) C.-I Peng & S.W. Chung (endemic and rare; Peng and Chung, 1998). Other plants such as Sarcococca saligna (D. Don) Muell.-Arg. [Buxaceae; endangered; Lu, 1996], Listera kuanshanensis H.J. Su [Orchidaceae; endemic and rare; Su, 1999], Ponerochis tominagai (Hayata) H.J. Su & J.C. Chen [Orchidaceae; endemic; Su and Chen, 2000], Woodsia okamotoi Tagawa [Athyriaceae; endemic and critically endangered; Moore, 1999], Polystichum xiphophyllum (Baker) Diels [Dryopteridaceae; critically endangered; Moore, 2000], Epilobium nankotaizanese Yamam. [Onagraceae; rare, alpine endemic; Hsu and Lu, 1984] are found also on Mt. Kuanshan.

glabrous. Ray florets 5 (-6), tube yellow, ca. 8.5 mm long, rays yellow, 9-14 mm long, ca. 3.5 mm broad, 3-denticulate at apex, 4-veined; disc florets ca. 14-15, corolla yellow, 7-8 mm long, tube 4-5 mm long, limb infundibuliform, lobes oblong-lanceolate, 1-1.5 mm long, acute, papillose at apex. Anthers ca. 2.5 mm long, shortly obtusely auriculate at the base, apical appendages ovate-lanceolate. Achenes cylindrical, 2-3 mm long, sparsely hirtellous on ribs. Flowering Aug-Oct.

Additional specimens examined. TAIWAN. Kaohsiung Hsien, Taoyuan Hsiang, path side from Southern Cross-island Hwy to Kuanshan, ca. 3,000-3,200 m, 23°13'15" N, 120°54'07" E, associated with Tsuga chinensis, Chamaecyparis formosensis, Trochodendron aralioides, Parasenecio monantha, Stranvaesia niitakayamensis, Rubus hayata-koidzumii, Viburnum taitoense, Yushania niitakayamensis, Erigeron morrisonensis, 2 Oct 1994, S. W. Chung s. n (HAST, NCUF, TAIF); 3026 cottage to Kuanshan, 2 Oct 1994, S. W. Chung 101 (TAIF); Oct 1997, M. J. Wu & S. F. Huang 5417 (TAI); 23°13'15" N, 120°54'07" E, on mountain ridge, numerous, in alpine bamboo grassland, roadside/pathside, middle humidity, slightly shaded, 11 Oct 1996, C. K. Liou et al. 367 (TAIF).

Botanical Bulletin of Academia Sinica, Vol. 43, 2002

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Figure 4. Distribution map of Senecio kuanshanensis in Taiwan.

Senecio kuanshanensis is a distinct member of sect. Crociseris (Reichenb.) Hall. et Wohlf. ser. Nemorenses Gagnidze (cf. Chen, 1999). Although in habit it is somewhat similar to S. morrisonensis Hayata, it is clearly distinct in having the middle cauline leaves deeply bipinnatipartite to tripinnatipartite (vs. serrate to coarsely dentate or deeply pinnately lobed), longer peduncles (3-7 cm vs. 0.5-2[-3] cm), longer involucres (8-10 mm vs. 4.5-6 mm), and larger floral parts, such as the narrow tube of the disc florets 4-5 mm long (vs. 3-3.5 mm long), and the rays of the ray florets 9-14 mm long (vs. 5.5-7.2 mm long).

Acknowledgments. Contribution No. 205 of Taiwan Forestry Research Institute. This study was supported in part by research grants from Academia Sinica and Council of Agriculture, Taiwan, to Ching-I Peng. We thank Kuo-Fang Chung (HAST; currently at MO) for collecting the type specimens and taking field photographs; Jr-Jen Chen (HAST) for technical assistance with the line drawing and the distribution map; and Shann-Jye Moore (TNU) and Tsai-Wen Hsu (TESRI) for helpful discussions. We are grateful to Roy Gereau (MO) for assistance with the Latin diagnosis. We are indebted to David E. Boufford (GH) and Thomas G. Lammers (OSH) for their helpful reviews on the manuscript.

Literature Cited

Barkley, T.M., B.L. Clark, and A.M. Funston. 1996. The segregate genera of Senecio sensu lato and Cacalia sensu lato (Asteraceae: Senecioneae) in Mexico and Central America. In D. J. N. Hind and H. J. Beentje (eds.), Compositae: Systematics. Proceedings of the International Compositae Conference, Kew, 1994. Vol. 1. Royal Botanic Gardens,

Chung and Peng — Senecio kuanshanensis (Asteraceae)