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Phytotaxa 175 (5): 293–297 www.mapress.com/phytotaxa/ Copyright © 2014 Magnolia Press Article ISSN 1179-3155 (print edition) PHYTOTAXA ISSN 1179-3163 (online edition) http://dx.doi.org/10.11646/phytotaxa.175.5.9 Polystichum hagiangense (subg. Haplopolystichum; Dryopteridaceae), a new fern species from Ha Giang Province, northern Vietnam NGAN THI LU1*, LIANG ZHANG2* & LI-BING ZHANG3# Department of Botany, Vietnam National Museum of Nature, Vietnam Academy of Science and Technology, 18th Hoang Quoc Viet Road, Cau Giay, Ha Noi, Việt Nam. 2 Chengdu Institute of Biology, Chinese Academy of Sciences, P.O. Box 416, Chengdu, Sichuan 610041, China. 3 Missouri Botanical Garden, P.O. Box 299, St. Louis, Missouri 63166-0299, U.S.A. * Co-first authors # Author for correspondence: Libing.Zhang@mobot.org 1 Abstract A new fern species, Polystichum hagiangense belonging to P. subg. Haplopolystichum (Dryopteridaceae), is described and illustrated from Ha Giang Province in northern Vietnam. Polystichum hagiangense is most similar to P. minutissimum by having a small habit (lamina 3.6–5.8 × 1.0–1.6 cm), but the former has the widest part of the lamina close to the base and ovate and larger pinnae (5.3–8.2 × 3.2–5.8 mm). In contrast, the latter has the widest part of the lamina above the middle and nearly rectangular and smaller pinnae (2.9−5.8 × 2.8−4.5 mm). Also, the two species have different ecological requirements. Polystichum hagiangense was found on limestone cliffs in forest at an elevation of 1290 m with dry and light conditions, while P. minutissimum grows on dripping limestone walls and stalactites inside a karst cave at an elevation of 750 m with humid and shady conditions. Polystichum hagiangense is currently known only from a single population occurring at Bat Dai Son community in Ha Giang Province, northern Vietnam, and would be classified as Critically Endangered (CR), following IUCN Red List criteria. Key words: Limestone flora, pteridophytes, Dryopteridaceae Introduction Estimated to contain ca 500 species worldwide (Zhang 2012, Zhang & Barrington 2013), Polystichum Roth (1799: 31; Dryopteridaceae) is one of the largest fern genera. Species of Polystichum are common in the temperate and subtropical lowlands and montane to alpine regions in the Northern Hemisphere, especially in southern and southwestern China, the Himalaya, Japan and Vietnam; a rich diversity of Polystichum is also found in Central and South America. Fifteen species of Polystichum have been listed in a recent checklist of ferns of Vietnam (Phan 2010) and ten new records of Polystichum have been reported from that country (Lu et al. 2014). During a visit to herbaria­­ in Hanoi, we identified an undescribed species of Polystichum growing on limestone cliffs in Ha Giang Province, northern Vietnam, which is described below. Taxonomy Polystichum hagiangense Li Bing Zhang, Ngan T. Lu & Liang Zhang, sp. nov. (Figure 1) Polystichum hagiangense is most similar to P. minutissimum Li Bing Zhang & H.He (2009: 353) by having a small habit (lamina 3.6–5.8 × 1.0–1.6 cm) and the leaves are appressed to the substrate, but the first has the widest part of the lamina close to the base and ovate and larger pinnae (5.3–8.2 × 3.2–5.8 mm). In contrast, the latter has the widest part of the lamina above the middle and nearly rectangular, smaller pinnae (2.9−5.8 × 2.8−4.5 mm). Type:—VIETNAM. Ha Giang Province: Bat Dai Son Community, Bat Dai Son Provincial Protected Area, ridge north of Bat Dai Son border station, 23°09’11’’N/104°59’06’’E, on sheer limestone cliff, 1290 m, 11 February 2001, D. K. Harder, N. T. Hiep, L. V. Averyanov & P. K. Loc 6162 (holotype HN!, isotypes LE, MO). Accepted by Maarten Christenhusz: 11 Jul. 2014; published: 15 Aug. 2014 293 on the acroscopic pinnae bases and anastomosing venation can also be found in both genera. However, species of Cyrtomium have an apical pinna somewhat dissected at the base (rarely a simple lamina), while those of Polystichum always have a pinnatifid apical pinna (Zhang et al. 2013) except P. fraxinellum (Christ) Diels (1899: 194) and P. minimum (Y.T. Hsieh) Zhang (2012: 58; see Zhang & Barrington 2013). Polystichum hagiangensse is clearly a member of Polystichum in having a pinnatifid apical pinna (Fig. 1). In addition to Polystichum hagiangensse, our recent field investigation and herbarium study showed that there are at least four species of P. subg. Haplopolystichum in Ha Giang Province: P. fraxinellum, P. minimum, and P. tenuius (Ching) Zhang (2012: 59). The latter three species were traditionally placed in the genus Cyrtogonellum Ching (1938; Hsieh 2001), which is now a section in Polystichum (Zhang & Barrington 2013: 678) because Cyrtogonellum is unambiguously resolved as part of Polystichum based on molecular data (Li et al. 2008, Liu et al. 2010, Zhang & He 2010). Polystichum minimum used to be called Cyrtogonellum inaequale (Christ) Ching (1938: 331), while P. tenuius replaces C. caducum Ching (1938: 330). Among these four species of Polystichum in Ha Giang Province, P. hagiangense stands out by having small and papery lamina that are appressed to the ground with ovate pinnae, while the other three all have erect or ascending leaves with much larger, leathery blades with obliquely ovate, ovatelanceolate or lanceolate pinnae. These four species can easily be distinguished using the following key: Key to species of Polystichum in Ha Giang Province, Vietnam 1. 1. 2. 2. 3. 3. Plant shorter than 10 cm long; leaves appressed to the substrate; lamina papery, ca. 3.6–5.8 × 1.0–1.6 cm; pinnae ovate.. .........................................................................................................................P. hagiangense Plant up to 50 cm tall or taller; leaves erect or ascending; lamina leathery, 8–28 × 2.5–3.5 cm or much larger; pinnae obliquely ovate, ovate-lanceolate or lanceolate. Lamina pinnate and with pinnatifid apex ............................................................................................................................. P. tenuius Lamina imparipinnate and with apical pinna of same shape as lateral pinnae. Pinnae 13–24 pairs, obliquely ovate; veins free.......................................................................................................................P. minimum Pinnae fewer than 8(–10) pairs, lanceolate; veins with few areoles along midrib.............................................................. P. fraxinellum Acknowledgements We thank L. V. Averyanov and D. Harder for providing information about the collection of the new species. We thank Emily Sessa for helpful comments and the curators of the herbaria HN and MO for providing access to material in their care. References Ching, R.C. (1938) A revision of the Chinese and Sikkim-Himalayan Dryopteris with reference to some species from neighbouring regions. Bulletin of the Fan Memorial Institute of Biology/Botanical Series 8: 327–331. Diels, L. (1899) Polypodiaceae. In: Engler, H.G.A. & Prantl, K.A.E. (Eds.) Die Natürlichen Pflanzenfamilien vol. 1(4): 139–339. IUCN (International Union for Conservation of Nature and Natural Resources). (2008) IUCN Red List Categories and Criteria, vers. 7, ed. IUCN. Gland, Switzerland and Cambridge, United Kingdom. Hsieh, Y.-T. (2001) Cyrtogonellum. In: Wu, C.-Y. (Ed.) Flora Reipublicae Popularis Sinicae. vol. 5(2). Science Press, Beijing, pp. 177–182. Li, C.-X., Lu, S.-G. & Barrington, D.S. (2008) Phylogeny of Chinese Polystichum (Dryopteridaceae) based on chloroplast DNA sequence data (trnL-F and rps4-trnS). Journal of Plant Research 121: 19–26. http://dx.doi.org/10.1007/s10265-007-0120-1 Liu, H.-M., Zhang, X.-C., Wang, W. & Zeng, H. (2010) Molecular phylogeny of the endemic fern genera Cyrtomidictyum and Cyrtogonellum (Dryopteridaceae) from East Asia. Organisms, Diversity & Evolution 10: 57–68. http://dx.doi.org/10.1007/s13127-010-0010-6 Lu, T.N., Zhang, L. & Zhang, L.-B. (2014) Ten new records of Polystichum (Dryopteridaceae) for Vietnam and lectotypification of Polystichum atroviridissimum and P. fimbriatum. Phytotaxa 164: 115–123. http://dx.doi.org/10.11646/phytotaxa.164.2.5 Phan, K.L. (2010) The updated checklist of the fern flora of Vietnam following the classification scheme of A. Smith et al. (2006). Journal of Fairylake Botanical Garden 9(3): 1–13. 296 • Phytotaxa 175 (5) © 2014 Magnolia Press LU ET AL. Presl, C. (1836) Tentamen pteridographiae, seu genera filicacearum praesertim juxta venarum decursum et distributionem exposita. T. Haase, Prague, 290 pp., 12 pl. http://dx.doi.org/10.5962/bhl.title.47011 Roth, A.W. (1799) Tentamen Florae Germanicae vol. 3. I.G.Müller, Leipzig. Zhang, L.-B. (2012) Taxonomic and nomenclatural notes on the fern genus Polystichum (Dryopteridaceae) in China. Phytotaxa 60: 57–60. Zhang, L.-B. & Barrington, D.S. (2013) Polystichum. In: Wu, Z.-Y., Raven, P.H. & Hong, D.-Y. (Eds.) Flora of China. Vol. 2–3. Beijing: Science Press and St. Louis: Missouri Botanical Garden Press, pp. 629–713. Zhang, L.-B. & He, H. (2009) Polystichum minutissimum, sp. nov. (sect. Haplopolystichum, Dryopteridaceae): The smallest Polystichum found in a karst cave in China. Botanical Studies 50: 353–358. Zhang, L.-B. & He, H. (2010) Polystichum speluncicola sp. nov. (sect. Haplopolystichum, Dryopteridaceae) based on morphological, palynological, and molecular evidence with reference to the non-monophyly of Cyrtogonellum. Systematic Botany 35: 13–19. http://dx.doi.org/10.1600/036364410790862605 Zhang, L.-B., Wu, S.-G., Xiang, J.-Y., Xing, F.-W., He, H., Wang, F.-G., Lu, S.-G., Dong, S.-Y., Barrington, D.S., Iwatsuki, K., Christenhusz, M.J.M., Mickel, J.T., Kato, M. & Gilbert, M.G. (2013) Dryopteridaceae. In: Wu, Z.-Y., Raven, P.H. & Hong, D.-Y. (Eds.) Flora of China. Vol. 2–3. Beijing: Science Press and St. Louis: Missouri Botanical Garden Press, pp. 542–725. Polystichum hagiangense (Haplopolystichum) Phytotaxa 175 (5) © 2014 Magnolia Press • 297