Botanical Studies (2012) 53: 387-392.
SYSTEMATICS
Pouzolzia taiwaniana (Urticaceae), a new species from Taiwan
Ching-I PENG1*, Yoshiko KONO1, Chia-Jui CHEN2, Tian-Chuan HSU3, and Shi-Wen CHUNG3 *
1Herbarium, Biodiversity Research Center, Academia Sinica, Nangang, Taipei 115, Taiwan
2Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
3Division of Botanical Garden, Taiwan Forestry Research Institute, Taipei 100, Taiwan
(Received January 30, 2012; Accepted April 10, 2012)
ABSTRACT. Pouzolzia taiwaniana, a new species from southern Taiwan, is described and illustrated. So­matic chromosome number (2n = 28) is here reported. Pouzolzia taiwaniana resembles P. tuberosa Wight in having tuberous roots, but differing in being a much smaller plant, usually less than 30 cm (vs. 30-180 cm) long, leaves 1-2 cm (vs. 2.5-7.5 cm) long, cordate or broadly ovate (vs. elliptic-lanceolate), basal lateral veins reaching the middle part of leaf margin (vs. reaching leaf apex). Pouzolzia taiwaniana was first discovered in a forested watershed area in 1990. It then comprised only a handful of individuals on a moist shady rocky slope. Unfortunately, the habitat was subsequently destroyed by landslides accompanying typhoons that hit Taiwan. In 2011 it was rediscovered in a landscape reserve 30 km south of where it was first collected. Pouzolzia taiwaniana is endemic to Taiwan. The only known extant population is on a mudstone slope that is prone to erosion and landslides. The area of distribution is approximately 50 x 10 m2 and contains less than 100 plants. According to IUCN Red List criteria, P. taiwaniana is considered to be Critically Endangered.
Keywords: Chromosome number; New species; Pouzolzia taiwaniana; Pouzolzia tuberosa; Rare species; Tai­wan; Taxonomy; Urticaceae.
INTRODUCTION
Scanning electron microscopy
The genus Pouzolzia Gaudich. (tribe Boehmerieae, Ur­ticaceae) consists of 35 species and 15 infraspecific taxa (Wilmot-Dear and Friis, 1996). Two species, P. elegans Wedd. and P. zeylanica (L.) Benn., were recorded in Flora of Taiwan, 2nd ed. (Yang et al., 1996). Pouzolzia elegans has since been treated at varietal rank under P. sanguinea (Blume) Merr. because there are intermediates in leaf shape and leaf margin characters in plants from Taiwan, Yunnan, and Nepal, and there is only partial geographic separation from P. sanguinea (Chen et al., 2003). In this paper we report the discovery of a new species of Pouzol-zia from two localities in southern Taiwan. A careful study of the literature, herbarium specimens and plants grown in the experimental greenhouse supports its recognition as a new species, which we name Pouzolzia taiwaniana.
Fruiting perianth and achenes were mounted on a speci­men stub and observed using a scanning electron micro­scope with an accelerating voltage of 15 KV (Hitachi TM 3000) at the Taiwan Forestry Research Institute. A voucher specimen (Peng et al. 23133) is deposited at HAST.
Chromosome preparation
Somatic chromosomes were examined using root tips from plants of the type collection. Root tips were pre-treated in 2 mM 8-hydroxyquinoline solution at 15-18°C for 6-8 h, then fixed overnight in a 3:1 ethanol-acetic acid solution below 4。C. Chromosomes were macerated and stained in 2% acetic orcein with 1N hydrochloric acid (10:1) and observed. Classification of chromosome mor­phology is based on the position of the centromere follow­ing Levan et al. (1964). A voucher specimen (Peng et al. 23133) is deposited at HAST.
MATERIALS AND METHODS
Living materials of Pouzolzia taiwaniana were col­lected from Taiwan. Type specimens have been preserved in the Herbarium of Academia Sinica, Taipei (HAST) and the Taiwan Forestry Research Institute (TAIF).
NEW SPECIES
Pouzolzia taiwaniana C.-I Peng & S. W. Chung, sp. nov. -TYPE. TAIWAN. Kaohsiung Hsien, Liukuei District, Shihbaluohanshan (十八羅漢山，literally, 'Eighteen-Buddhist-Disciple Peaks'), scattered on mudstone-rich slope by a stream in a badland region, E120° 38′32〃, N22° 56′19〃,ca. 235 m alt., 7 July 2011, Ching-I Peng
*Corresponding authors: E-mails: bopeng@sinica.edu.tw (Ching-I PENG); biflora@gmail.com (Shih-Wen CHUNG).
388
Botanical Studies, Vol. 53, 2012
23133, accompanied by Chien-I Huang, Shih-Wen Chung, Tien-Chuan Hsu & Li-Hsien Yang (holotype: HAST; isotypes: PE, TAIF).台灣霧水葛
Figures 1, 2
Description. Herbs, perennial, matted creeping, laxly branched from tuberous rootstock. Tubers oblong, to ca. 1.6 cm long, 9 mm across. Stems ca. 0.7-1 mm in diam­eter, densely white tomentose, becoming glabrescent,
Figure 1. Pouzolzia taiwaniana C.-I Peng & S. W. Chung. A, Habit; B, Leaf; C, staminate flower; D, Pistillate flower; E, Fruiting perianth; F, Achene.
PENG et al. ― Pouzolzia taiwaniana, a new species from Taiwan 389
Figure 2. Pouzolzia taiwaniana C.-I Peng & S. W. Chung. A, Habitat; B, Habitat and habit; C, Portion of stem showing leaves and a staminate flower; D, Portion of a branch showing staminate and pistillate flowers; E, Portion of a branch showing a flower bud and a filiform stigma; F, achene; G, Fruiting perianth; H, Uncinate-tipped hairs on perianth; I, Straight hairs on perianth.
390
Botanical Studies, Vol. 53, 2012
rooting freely at nodes, forming secondary tubers where rooting. Leaves membranaceous, alternate, blade cordate or broadly ovate, 1-2 cm long, 0.9-1.5 cm wide, base rounded to cordate, margin entire, apex subacute, 3-nerved from base; basal pair of lateral veins rising to about half leaf length ; upper lateral veins 1 or 2 on each side of midvein, alternate, venation impressed adaxially, elevated abaxially; upper surface puberulous, lower surface gla­brous, veins sparsely puberulous; petioles reddish, 3-9 mm long, puberulous; stipules triangular, ca. 2 mm long, 1 mm wide, sparsely brownish puberulous. Inflorescence axillary fascicles of 1-4 flowers, staminate and pistillate flowers in the same cluster; subtending bracteoles triangular, ca 0.8 mm long. Staminate flowers ca. 8-10 mm across, perianth lobes 4, greenish white, sometimes reddish; ma­ture buds globose, sparsely puberulous. Pistillate flowers: perianth tubular, often ovoid, beaked, apex 2-toothed; stigma filiform, 2.2-2.4 mm long. Fruiting perianth ovoid, ca. 1 mm long, 0.6 mm across, covered with intermixed straight hairs and uncinate-tipped hairs (Figure 2: F-I, SEM images). Fruits ovoid, ca. 1 mm long, 0.6 mm wide, surface glabrous, beaked apically. Somatic chromosome number, 2n = 28.
To aid in identification, we provide the following key to distinguish the species of Pouzolzia in Taiwan.
1. Shrubs or small trees; leaves serrate .......1. P. sanguinea
1. Herbs or subshrubs; leaves entire.
2. Herbs, prostrate and rooting on nodes; leaves lternate, cordate or broadly ovate................. 2. P. taiwaniana
2. Herbs, ascending, or subshrubs; leaves opposite and alternate, ovate to lanceolate.............3. P. zeylanica
Additional specimens examined. TAIWAN. Tainan Hsien, Nanhsi Hsiang, watershed area of Tsengwen Dam, along a trail from bridge #4 , moist, shady slope, E120。 30'0〃, N23。 14'19〃， elev. 160 m, 10 Aug 1990, Ching-I Peng 13423 (HAST). Kaohsiung Hsien, Liukuei District, Shihpalohanshan, E120° 38′32〃, N22° 56′19〃, ca. 235 m alt., 7 July 2011, Shih-Wen Chung 10389 (TAIF).
Figure 3. Latitudinal and altitudinal distributions of Pouzolzia taiwaniana (circles) in Taiwan.
Habitat, distribution and IUCN Red List category. Pouzolzia taiwaniana was first discovered by Ching-I Peng in a forested watershed area at a dam in Tainan Hsien during a field survey in 1990. The population consisted of only a handful of individuals on a moist shady rocky slope. Unfortunately, the habitat was subsequently destroyed by landslides accompanying typhoons. Subsequent attempts to relocate P. taiwaniana failed, but in 2011, guided by Mr. Li-Hsien Yang, an amateur plant enthusiast, we discovered a population in a landscape reserve in Kaohsiung Hsien ca. 30 km south of where it was first discovered (Figure 3). The plants occurred scatteredly on a semishaded mud-stone-rich slope by a stream in a badland region.
Pouzolzia taiwaniana is endemic to Taiwan. Although it is located within a protected area for landscapes, the only extant habitat is a mudstone slope that is prone to erosion and landslides. The area of distribution is approximately 50 x 10 m2 and contains fewer than 100 plants. According to IUCN Red List criteria, P. taiwaniana is considered to be Critically Endangered (IUCN, 2001).
Morphological comparison. Pouzolzia taiwaniana resembles P. tuberosa Wight from India in the tuber­ous roots, but differs in being a much smaller, prostrate plant, usually with stems less than 30 cm (vs. 30-180 cm) long, leaves 1-2 cm (vs. 2.5-7.5 cm) long, base cordate or broadly ovate (vs. elliptic-lanceolate), basal lateral veins reaching the middle of the leaf (vs. reaching leaf apex).
Figure 4. Somatic chromosomes at mitotic metaphase of Pou-zolzia taiwaniana C.-I Peng & S. W. Chung (2n = 28, from Peng et al. 23133, HAST). A, Microphotograph. Scale bar = 5 (im; B, Somatic chromosomes serially arranged by their chromosome length and the centromeric position. Scale bar = 2 (m.
PENG et al. ― Pouzolzia taiwaniana, a new species from Taiwan
391
Chromosome cytology. Our study of somatic chromo­somes of Pouzolzia taiwaniana revealed 2n = 28 (Figure 4). The 28 chromosomes at mitotic metaphase gradually varied from ca. 1.6 to 2.2 (m long. Most chromosomes appeared to be metacentric, however, the exact centromere position of several shorter chromosomes could not be de­termined. Satellites were not observed.
LITERATURE CITED
Chang, K.C., C.C. Wang, S.L. Deng, Y. Kono, F.Y. Lu, and C.-I
Peng. 2011a. Cotoneaster rosiflorus (Rosaceae), a new species from Taiwan. Bot. Stud. 52: 211-218.
Chang, K. C., C.M. Wang, S.L. Deng, and C.C. Wang. 2011b. A
new species Cotoneaster chingshuiensis (Rosaceae) from Taiwan. Taiwania 56: 125-131.
Chao, C.T., H.Y. Tzeng, and Y.H. Tseng. 2012. Maianthemum harae (Asparagaceae), a new species from Taiwan. Ann. Bot. Fennici 49: (in press).
Chen, J.R., I. Friis, and C.M. Wilmot-Dear. 2003. Pouzolzia. In Z.Y. Wu, P.H. Raven and D.Y. Hong (eds.), Flora of China, Vol. 5. pp. 175-178.
Chung, S.W., T.C. Hsu, and C.-I Peng. 2010. Phacellanthus
(Orobanchaceae), a newly recorded genus in Taiwan. Bot.
Stud. 51: 531-536. Hsu, T.W., Y. Kono, T.Y. Chiang, and C.-I Peng. 2011.
Ypsilandra (Melanthiaceae; Lilliaceae sensu lato), a new generic record for Taiwan. Bot. Stud. 52: 99-104.
Hsu, T.C. and S.W. Chung. 2012. Tripterospermum hualiense (Gentiaceae), a new species from Taiwan. Taiwania 57:
183-187.
IUCN. 2001. IUCN Red List Categories and Criteria, Version
3.1. Prepared by the IUCN Species Survival Commission. IUCN, Gland, Switzerland, and Cambridge, United King­dom.
Levan, A., K. Fredga, and A.A. Sandberg. 1964. Nomenclature for centromeric position on chromosomes. Hereditas 52:
201-220.
Lin, T. P. and W.M. Lin. 2011. Newly discovered native orchids of Taiwan (IV). Taiwania 56: 315-322.
Sharma, A.K. 1970. Annual report, 1967-1968. Res. Bull. Univ. Calcutta (Cytogenetics Lab.) 2: 1-50.
Sharma, M.L. and P.N. Mehra. 1977. In IOPB chromosome number reports LVII. Taxon 26: 443-452.
Sharma, M.L. and P.N. Mehra. 1979. Chromosome numbers in some East Himalayan Urticaceae. Cytologia 44: 799-803.
Subramanian, D. and A. Thilagavathy. 1988. Cytotaxonomical studies of South Indian Urticaceae. Cytologia 53: 671-678.
Tseng, Y.H. and C.C. Wang. 2011. Alpinia oui (Zingiberaceae), a New Species from Taiwan. Novon 21: 270-273.
Wang, J.C. and C.T. Lu (eds.). 2012. Flora of Taiwan, Second Edition-Supplement. National Taiwan Normal University, Taipei, 414 pp.
Yang, Y.P., B.L. Shih, and H.Y. Liu. 1996. Urticaceae. In Edi­torial Committee of the Flora of Taiwan, Second Edition (eds.), Flora of Taiwan, 2nd edn., Vol. 2. Editorial Commit­tee of the Flora of Taiwan, Second Edition, Taipei, Republic of China, pp. 197-257.
In Taiwan, two species of Pouzolzia, P. elegans and P. zeylanica, were previously recognized (Yang et al., 1996). The chromosome number of P. zeylanica from southern India was reported as n = 12 and 2n = 24 (Subramanian and Thilagavathy, 1988). Pouzolzia taiwaniana differs not only morphologically, but also in chromosome number from P. zeylanica.
Chromosome numbers of n = 10, 11, 12, 13, 16, 26 and 2n = 20, 22, 24, 26, 48 from eight species of Pouzolzia have been reported by Sharma (1970), Sharma and Mehra (1977, 1979) and Subramanian and Thilagavathy (1988). Our finding of 2n = 28 in P. taiwaniana is the first report of this number for the genus. In previous reports, the species of Pouzolzia showed a serial variation in chromo-some number. Therefore, the basic chromosome number (x) of Pouzolzia cannot be determined.
Notes. One may be forgiven for thinking that Taiwan's flora is completely described given the currency of the two editions of Flora of Taiwan (1975-1979; 1994-2003) complemented by the Supplement to the Flora of Taiwan, 2nd ed. (Wang and Lu, 2012). The last treats nearly 300 species up to 2009. A cursory search of recent literature, however, indicates that considerable taxonomic diversity is still being discovered and described; e.g., new species in Rosaceae: Cotoneaster rosiflorus and C. chingshuien-sis (Chang et al., 2011a, b); Zingiberaceae: Alpinia oui (Tseng and Wang, 2011); Asparagaceae: Maianthemum harae (Chao et al., 2012); Gentianaceae: Tripterospermum hualiense (Hsu and Chung, 2012); four new species of Orchidaceae (Lin and Lin, 2011); new generic records for Taiwan in Melanthiaceae (Ypsilandra: Hsu et al., 2011) and Orobanchaceae (Phacellanthus: Chung et al., 2011). As can be seen, these novelties (including Pouzolzia tai-waniana reported here) are not restricted taxonomically, nor are they in life form or ecologically, ranging from seaside to alpine locations. While isolated limestone areas are relatively underexplored and understudied and are a priority, much taxonomic work remains even in this well studied flora.
Acknowledgments. The authors are grateful to Drs. David E. Boufford (A/GH), Jeremy Bruhl (NE) and Qiner Yang (IBSC) for improving the manuscript; Mr. Li Hsien Yang, a plant enthusiast, for relocating the rare species; Mr. Chien-I Huang (HAST) for field assistance; and Mr. Wen-Pen Leu for the handsome line drawing. This study was supported in part by a series of funding from the National Science Council, Taiwan to Ching-I Peng and an Aca-demia Sinica postdoctoral fellowship to Yoshiko Kono.
392
Botanical Studies, Vol. 53, 2012
臺灣蓴麻科新種植物：台灣霧水葛
彭鏡毅1 河野淑子1 陳家瑞2 許天銓3 鐘詩文3
1中央研究院生物多樣性研究中心植物標本館
2中國科學院植物研究所
3行政院農業委員會林業試驗所植物園組
本文發表臺灣南部發現的蓴麻科新種植物：台灣霧水葛(Pouzolzia taiwaniana)，並報導其染色體數
目（2n = 28)。此新種之形態略似印度產的塊莖霧水葛（P. tuberosa) ，二者雖都具塊莖，但新種的植株
甚小，匍匐而多分支，莖長可達30 cm ，葉長1-2 cm ，葉基心型或闊卵形，葉基側脈向上及於葉緣中
部；塊莖霧水葛植株長可達30-180 cm ，葉長2.5-7.5 cm ，葉橢圓至披針形，葉基側脈向上延伸至葉尖,
明顯可以區別。本文除提供台灣霧水葛之線繪圖、彩色圖版以及分布圖檢索表，並製作臺灣產本屬三種
植物的檢索表以利辨識。台灣霧水葛族群數量極為稀少，且其生育地為甚不穩定的惡地石礫陡坡，容易
受害，根據國際自然保育聯盟（IUCN)的評估準則，本種應列為嚴重瀕臨絕滅等級。
關鍵詞：染色體數目；新種；台灣霧水葛；塊莖霧水葛；稀有植物；臺灣；分類學；蓴麻科。