Polystichum loratum (Dryopteridaceae), a New Fern Species from Guizhou, China Hai He and Yong-Qing Yang College of Life Sciences, Chongqing Normal University, Shapingba, Chongqing 400047, China Li-Bing Zhang* Missouri Botanical Garden, P.O. Box 299, St. Louis, Missouri 63166-0299, U.S.A., and Chengdu Institute of Biology, Chinese Academy of Sciences, P.O. Box 416, Chengdu, Sichuan 610041, People’s Republic of China. *Corresponding author: libing.zhang@mobot.org ABSTRACT. A new fern species, Polystichum loratum H. He & Li Bing Zhang (Dryopteridaceae), is described and illustrated from limestone cliffs in northern Guizhou Province, China. Polystichum loratum is most similar to P. yaanense Liang Zhang & Li Bing Zhang in having narrowly ovate to lanceolate abaxial rachis scales. The new species is distinguished by its lorate leaf lamina, the oblong to narrowly ovate microscales (broad-type) on abaxial pinna surfaces, and the exindusiate sori, while P. yaanense has lanceolate leaf lamina, subulate microscales (narrow-type) on abaxial pinnae, and indusiate sori. Polystichum loratum is considered to be Critically Endangered (CR), based on IUCN Red List criteria. Key words: China, Guizhou, IUCN Red List, limestone flora, Polystichum. In the summer of 2011, Hai He and Yong-Qing Yang conducted fieldwork in northern Guizhou, China, to search for samples of Hypodematium glandulosum Ching ex K. H. Shing (Dryopteridaceae or Hypodematiaceae). On the way to the summit of Jindingshan of Zunyi City, a city famous for the 1935 Zunyi Meeting in modern Chinese revolutionary history, a species of Polystichum Roth (Dryopteridaceae) growing on limestone cliffs was collected and photographed, and photos, specimens, and DNA samples were sent to Li-Bing Zhang. After comparative morphological investigation, we conclude that the species is unknown to science, and it is described here. Polystichum loratum H. He & Li Bing Zhang, sp. nov. TYPE: China. Guizhou Province: Zunyi Prefecture, Zunyi City, Jindingshan Town, Xintugou Cun, Jiayanwo, 27846911.0299N, 106846914.2799E, 1150 m, on shaded & damp limestone cliffs, 2–3 m distant from the ground, NOVON 22: 166–169. PUBLISHED ON 23 June 2011, H. He & Y. Yang 1361 (holotype, CDBI; isotypes, CTC, MO). Figure 1. Diagnosis. Polystichum loratum H. He & Li Bing Zhang is most similar to P. yaanense Liang Zhang & Li Bing Zhang in having narrowly ovate to lanceolate abaxial rachis scales, but the new species is distinguished by its lorate leaf lamina (vs. lanceolate in P. yaanense), the oblong to narrowly ovate and broad-type microscales (vs. subulate and narrow-type in P. yaanense) on abaxial pinna surfaces, and the exindusiate sori. Plants perennial, caespitose, evergreen; rhizome ascending, 0.5–2.2 cm, 0.4–1.6 cm diam., with remnant bases of old petioles, scaly at the base of the petiole (but scales mostly worn out, incomplete, and much darker in color); adventitious roots dull brown when dry, 0.2–0.3 mm diam., nearly glabrous or occasionally covered with lanate scales, the longer roots once or twice branched with lateral rootlets to 1.8 cm. Leaves 8 to 18(to 25) per rhizome, (5.9–) 11.2–16.8 cm, leaf lamina appressed to substrate or ascending; petioles green, (0.5–)1.5–4.8 cm, 0.3–1.2 mm diam. at middle, densely covered with spreading scales; petiole scales generally 2.5–4.1 3 0.8–1.2 mm, ovate to lanceolate, thin and papery, brown, apex caudate, ending in a ca. 0.8 mm hairlike tip, base rounded and slightly peltate in attachment, scale margins with 0.5–0.8 mm wavy, hairlike outgrowths, mixed with smaller scales (fewer and mostly on adaxial petiole surface) deltoid to lanceolate, ca. 2 3 0.5 mm, margins and apex also with hairlike outgrowths and long hairlike tip; basal petiole scales worn and incomplete, similar to those on rhizome, mostly without marginal outgrowths and hairlike tips, thicker in texture and dark brown in color. Leaf lamina lorate, 1pinnate, (4.5–)7.5–12.5 3 0.9–1.5 cm, apex acuminate, 6 narrowed toward base from the mid-portion and tapering down; rachis 0.3–0.6 mm diam. at middle of lamina, without proliferous bulbils, green and concolorous as pinnae when fresh, yellowish green 30 NOVEMBER 2012. doi: 10.3417/2012045 Volume 22, Number 2 2012 He et al. 167 Polystichum loratum (Dryopteridaceae) from Guizhou, China Figure 1. Polystichum loratum H. He & Li Bing Zhang. —A. Habit. —B. Pinna. —C, D. Petiole scales. —E. Abaxial rachis scale. —F, G. Microscales (broad-type microscales) of pinnae. A–G drawn from the holotype H. He & Y. Hang 1361 (CDBI). when dry, densely covered with scales abaxially, sparsely scaly (especially at base of petiolules) adaxially; abaxial rachis scales ovate to lanceolate, similar to those of petiole but smaller, lighter in color and thinner in texture, adaxial rachis scales deltoid and subulate, dark brown, to 2 3 0.4 mm, hairlike outgrowths only at broadest base, margins nearly entire, apex caudate; pinnae nearly leathery, in (16 to)25 to 55 pairs, alternate, 1–2 mm apart, contiguous or imbricate (sometimes basal 1 to 6 pairs to 3 mm apart even if other pinnae are imbricate), asymmetrically rectangular to oblong (or slightly falcate toward apex), 3.5–6.5 3 1.8–3 mm, lowest pairs usually 1/2 to 2/3 as long as middle pinnae, asymmetrically deltoid or widely so, shortly petiolulate (petiolules to ca. 1 mm, attached to rachis at an acroscopic angle of ca. 168 Novon 608), basiscopic margins at angles of 758–1508 with rachis, the basiscopic base cuneate, acroscopic side 6 truncate (with a blunt auricle, sometimes auricle deeply incised to near midrib and forming a basal free cuneate-based lobe of ca. 2 3 1.8 mm with 2 or more small teeth at apex), forming angles of 908–1208 at the point of attachment to the petiolule, margins slightly cartilaginous, basiscopic side of pinnae nearly entire, distally curved toward apex, with 1 or 2 small teeth (distal margins sometimes curved with 2 to 3 undulations), acroscopic side of pinnae with 3 or 4 shallow teeth between the basal auricle tooth and pinna apex (sometimes also with 3 or more shallow or rarely deep undulations), apex rounded or acute (occasionally acuminate) and ending in a blunt tooth, all teeth without aristate tips, adaxial pinna surface glabrous (occasionally with 1 to 3 microscales), abaxial pinna surface sparsely covered with microscales (especially along veins); microscales oblong to narrowly ovate (Fig. 1F, G; broad-type microscales), 0.8–1.2 3 0.15–0.25 mm, light brown, membranous, apex extended by hairlike appendage, microscale margins irregularly erose, with the broadest part consisting of 6 to 8 lines of cells; venation of pinnae pinnate, visible abaxially and indistinct adaxially, lateral veins free, single or once forked. Sori terminal on lateral veins, 2 to 4(5) on acroscopic side, 0 or 1 on distal basiscopic side, 1.4–2.4 mm diam., mostly medial (between pinna margins and midrib), proximal 1 or 2 sori closer to pinna margins, occasionally all sori close to pinna margins, centers ca. 1.5 mm apart from one another, contiguous when mature; indusia absent; sporangia round, ca. 0.2 mm diam., walls ca. 0.1 mm thick, dark brown when mature; annuli with ca. 15 thickened cells; sporangial stalks ca. 0.3 mm; number of spores per sporangium unknown. Polystichum loratum was observed to grow either on shaded, damp limestone cliffs of a small gorge (Jiayanwo, the type locale) or on unshaded, damp cliffs under shrubs, as well as on the surfaces of carbonate sediment at the bottom of the mouth of a karst cave (Touniudong, Buffalo-Stolen Cave), at 1150–1300 m. Plants associated with the type of Polystichum loratum include the seed plants Boehmeria clidemioides Miq. var. diffusa (Wedd.) Hand.-Mazz. (Urticaceae), Briggsia mihieri (Franch.) Craib (Gesneriaceae), Elatostema involucratum Franch. & Sav. (Urticaceae), Hemiboea subcapitata C. B. Clarke (Gesneriaceae), Saxifraga stolonifera Curtis (Saxifragaceae), Begonia L. (Begoniaceae), Petrocosmea Oliv. (Gesneriaceae), and Polygonum L. (Polygonaceae). Fern associates were Hypodematium crenatum (Forssk.) Kuhn (Hypodematiaceae), Cyrtomium fortunei J. Sm., Polystichum craspedosorum (Maxim.) Diels, and P. erosum Ching & K. H. Shing (Dryopteridaceae). Distribution and ecology. Polystichum loratum is currently known only from Xintugou, an area close to Jindingshan Town north of Zunyi City in northern Guizhou. Jindingshan is a scenic mountain near Zunyi, and the area called Xintugou lies within a valley at the western portion of the mountain range; the northern side of Xintugou includes elevated limestone cliffs, where P. loratum is found. The areas surrounding Xintugou correspond to a general karst landscape, but without so many limestone outcrops. Given the similarity of the adjacent karst topography to the Xintugou area, we expect that similar habitats, and thus the same plants, could possibly be found during future fieldwork. IUCN Red List category. Only four populations of Polystichum loratum have been found at Xintugou, with a total of an estimated 180 individuals (with the smallest population having ca. 30 individuals). The new species clearly should be classified as Critically Endangered (CR), based on current information and according to IUCN Red List criteria (IUCN, 2008). However, a more extensive search is needed to accurately assess the conservation status of the new species. Etymology. The species epithet is taken from the Latin word ‘‘loratum,’’ meaning ‘‘lorate,’’ referring to the general lorate outline of its lamina. Taxonomic notes. Polystichum loratum has 1pinnate leaves and is clearly a member of Polystichum sect. Haplopolystichum Tagawa (1940) s.l. (Zhang & He, 2009). The narrow strap-shaped, lorate outline of the leaf lamina of P. loratum is reminiscent of that of P. subacutidens Ching ex L. L. Xiang, which is in the same section and is distributed from southern China to northern Vietnam. However, P. subacutidens has filiform rachis scales and linear or filiform microscales on pinnae that clearly differ from the new species. In Polystichum sect. Haplopolystichum s.l., P. loratum is one of only two species with ovate to lanceolate rachis scales. The other species in the section with ovate to lanceolate rachis scales is P. yaanense (Zhang et al., 2012). In spite of the similar shapes of the rachis scales, these two species can be easily distinguished morphologically from each other. Most important, P. loratum has oblong to lanceolate Volume 22, Number 2 2012 He et al. 169 Polystichum loratum (Dryopteridaceae) from Guizhou, China microscales on pinnae abaxially and exindusiate sori, while P. yaanense has subulate microscales on pinnae abaxially and indusiate sori. In addition, P. loratum has linear leaf lamina and slightly cartilaginous pinna margins, while P. yaanense has lanceolate leaf lamina and noncartilaginous pinna margins. Polystichum yaanense occurs in Ya’an Prefecture, Sichuan. The morphological differences between P. loratum and P. yaanense are elaborated in the following key. Acknowledgments. This project was supported by the National Natural Science Foundation of China (#31070187) and the Chongqing Municipality Science and Technology Commission (#cstc2011jjA00006) to H.H. and by a grant from the Open Laboratory of Ecological Restoration and Biodiversity Conservation of Chengdu Institute of Biology, Chinese Academy of Sciences, to L.-B.Z. We are indebted to Yushan Li for help with fieldwork, Faqiang Lü for the line drawing, and two anonymous reviewers, as well as Sara Fuentes and Victoria Hollowell, for helpful comments. Special thanks go to the curators of CDBI, CTC, and MO for giving us access to the materials in their care. KEY WITH SPECIES OF POLYSTICHUM SECT. HAPLOPOLYSTICHUM S.L. OVATE TO LANCEOLATE RACHIS SCALES IN CHINA TO 1a. Leaf lamina lanceolate; pinnae stiff, nearly transparent when dry with veins being visible adaxially, not cartilaginous on margin; microscales of pinnae subulate; sori indusiate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. yaanense 1b. Leaf lamina lorate; pinnae soft, not transparent when dry with veins being indistinct adaxially, slightly cartilaginous on margin; microscales of pinnae oblong to narrowly ovate; sori exindusiate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P. loratum Paratypes. CHINA. Guizhou: Zunyi City, Jindingshan Town, Xintugou, Dongwan, Touniudong (Buffalo-Stolen Cave), 1300 m, 23 June 2011, H. He & Y. Yang 1343, 1345, 1347, 1354 (CDBI, CTC); Jiayanwo, 1150–1200 m, 23 June 2011, H. He & Y. Yang 1356, 1360 (CDBI, CTC). Literature Cited IUCN. 2008. IUCN Red List Categories and Criteria, Version 7. Prepared by the IUCN Species Survival Commission. IUCN, Gland, Switzerland, and Cambridge, United Kingdom. Tagawa, M. 1940. Polystichum of Japan, Korea, and Formosa, I. Acta Phytotax. Geobot. 9: 119–138. Zhang, L., L.-B. Zhang & J. Liu. 2012. Polystichum yaanense (Dryopteridaceae), a remarkable new species from Sichuan, China. Novon 22(2): 244–249. Zhang, L.-B. & H. He. 2009. Polystichum peishanii (sect. Haplopolystichum, Dryopteridaceae): A new fern species from a limestone area in Guizhou, China. Bot. Stud. (Taipei) 50(1): 101–106.