Wedelia trilobata (L Bangladesh J. Plant Taxon. 16(2): 99-113, 2009 (December) © 2009 Bangladesh Association of Plant Taxonomists PHENETIC RELATIONSHIP BETWEEN LEPISORUS (J.SM.) CHING (PTERIDOPHYTA: POLYPODIACEAE) AND ITS RELATED GENERA WANNACHAI CHATAN1, THAWEESAKDI BOONKERD1,2 AND BERNARD R. BAUM3 Biological Sciences Program, Faculty of Science, Chulalongkorn University, Pathumwan, Bangkok 10330, Thailand. Keywords: Lepisorus; Paragramma; Platygyria; Cluster analysis; Canonical discriminant analysis. Abstract Multivariate analyses based on morphological and anatomical characters have been performed to investigate the phenetic relationship and to clarify the circumscriptions of the genus Lepisorus (J.Sm.) Ching and its related genera, namely Neocheiropteris Christ, Paragramma T. Moore and Platygyria Ching & S.K. Wu. The dendrogram of cluster analysis separated the plants into three groups at Gower similarity coefficient 0.75. Group 1 and Group 2 consisted of Neocheiropteris palmatopedata (Baker) H. Christ and four species of Platygyria, respectively. Group 3 was Neocheiropteris ensata Ching and two species of Paragramma deeply embedded in the Lepisorus s.s. Canonical discriminant analysis supported the classification inferred from the clustering results. Based on these results, Platygyria and N. palmatopedata should be recognized as distinct genera. On the other hand, N. ensata and the genus Paragramma should be merged to the genus Lepisorus. Introduction Lepisorus (J.Sm.) Ching s.l. (including Paragramma T. Moore) is the fern genus of Polypodiaceae, which comprised approximately 30 species (Verdcourt, 2001) or 70 species (Lin, 2000) naturally occurring in the tropical and subtropical Old World and extending northwards to the Far East of Russia with one species in Hawaii (Verdcourt, 2001). Lepisorus s.s. (excluding the Paragramma), however, was first treated by J. Smith in 1846 (in Zink, 1993) as a section of a highly heterogeneous Drynaria, and Ching (1933) raised the section Lepisorus to generic rank. The common features of Lepisorus s.l. are epiphytic, epilithic or terrestrial ferns with short- to long-creeping rhizome covered by clathrate scales; laminas are simple, entire and mostly naked; and sori are borne in single rows on either side of the midrib, and covered by clathrate paraphyses (Hennipman et al., 1990; Verdcourt, 2001). Until now, the generic circumscription of Lepisorus has remained controversial because it sometimes included or excluded its related taxa, namely Paragramma and Platygyria Ching & S.K. Wu. In addition, Platygyria, which is closely related to Lepisorus s.l. sometimes merged with the genus Neocheiropteris Christ. 1 Department of Botany, Faculty of Science, Chulalongkorn University, Pathumwan, Bangkok 10330, Thailand. E-mail: wannachaichatan@gmail.com 2 Corresponding author. E-mail: bthawees@gmail.com 3 Eastern Cereal and Oilseed Research Centre, Agriculture and Agri-Food Canada, Ottawa, Ontario, Canada. E-mail: bernard.baum@agr.gc.ca 100 CHATAN et al. The genus Paragramma was founded by T. Moore in 1857 using P. longifolia T. Moore as the type species (Copeland, 1947). Until now, its separation from the Lepisorus s.l. has never been clear (Hovenkamp, 1998). The recognition to keep it as a distinct genus was followed by Ching (1940), Copeland (1947) and Pichi Sermolli (1977). Copeland (1947) used the combination characters of soral shape and the presence of lamina scales to distinguish the Paragramma from Pleopeltis (including Lepisorus s.s.). Two species, namely Paragramma balteiformis Copeland and the type species, were recognized by Copeland (1947). In contrast, Holttum (1954), Tagawa and Iwatsuki (1989), Hennipman et al. (1990) and Hovenkamp (1998) consented to unite Paragramma with Lepisorus s.s. The Chinese fern genus Platygyria was erected based on the P. waltonii (Ching) Ching & S.K. Wu (Ching and Wu, 1980) and the characters of sporangium were used as the important defining characters. So, five species, namely Platygyria sinuata Ching & S.K. Wu, P. inaequibasis Ching & S.K. Wu, P. variabilis Ching & S.K. Wu, P. kongtingensis Ching & Y.X. Lin and P. muliensis Ching & S.K. Wu were recognized (Ching and Wu, 1980; Ching et al., 1983). Likewise, Zhang et al. (2003) agreed to keep Platygyria at the genus level and treated P. kongtingensis and P. muliensis as two synonyms of P. variabilis. However, there were other two treatments of the genus Platygyria. The first involved reducing Platygyria under Neocheiropteris (Ching, 1933; Hennipman et al., 1990), while the second involved merging Platygyria with Lepisorus s.s. (Yu and Lin, 1997). Therefore, the merging of Platygyria with either Lepisorus or Neocheiropteris, or its acceptance as a distinct genus needs to be assessed. As the controversial generic circumscription or position of these taxa shown above, until now, there has been no taxonomic study aimed at clarifying these problems. Therefore, the objectives of the present work were, 1) to investigate the phenetic relationship and use the result to determine the suitability of the generic circumscription or position of the Lepisorus and the other three related genera, i.e. Neocheiropteris, Paragramma and Platygyria, and 2) to determine the important morphological or anatomical characters that can be used to distinguish these taxa. With the aforesaid objectives in mind, both cluster analysis (CA) and discriminant analysis (DA) were performed based on 53 qualitative and quantitative characters examining 487 herbarium specimens. Materials and Methods Plant materials: In the present study, about 2500 herbarium specimens collected from around the world and housed at the herbaria in Europe (BM, E, L, K and P) and Asia (BCU, BKF, BK, PE, KUN, PYU and TI) were studied (Herbarium abbreviations according to Holmgrens and Holmgrens, 2008). A total of 487 complete specimens were selected for examination constituting the Operational Taxonomic Units (OTUs). (Some PHENETIC RELATIONSHIP BETWEEN LEPISORUS AND RELATED GENERA 101 representative specimens are listed in Appendix I. A complete list is available upon request from the corresponding author.) The specimens that were included in this study belonged to Lepisorus s.s. and its related three genera, namely Neocheiropteris, Paragramma and Platygyria. These specimens included specimens of the type species of each genus. Most specimens were identified by examining type specimens or identifications were made by consulting literature, e.g. Ching (1933), Tagawa and Iwatsuki (1989), Zink (1993), Shieh et al. (1994), Hovenkamp (1998), Verdcourt (2001), and Zhang et al. (2003). Morphological and anatomical characters: Fifty-three morphological and anatomical characters were examined for each of the 487 specimens. Measurement was carried out by using a Keiba digital caliper No. 111-101HB or specimens were measured under Stereomicroscope (Zeiss Stemi DV4) and light microscopes (Olympus CH30). Of these characters, 26 were quantitative including four ratio characters (Appendix II), and 27 were qualitative characters scored as binary or multi-state characters (Appendix III). These characters and their states were used to construct a data matrix. Phenetic analysis: The phenetic relationships among the taxa were investigated by two types of multivariate analysis: cluster analysis (CA) and canonical discriminant analysis (DA). The CA was performed by using an unweighted pair-group method with arithmetic average (UPGMA) clustering implemented in the Multivariate Statistical Package (MVSP), Version 3.13 (Kovack Computing Services) to place individual specimen into groups. Because the characters submitted to analysis were both quantitative and qualitative, the Gower similarity coefficient (GSC) was calculated (Gower, 1971) and clustered by the group-average method of the MVSP program. A subset of characters that maximized differences among the groups determined by CA or other groups (i.e. Lepisorus s.s., Paragramma, Platygyria and Neocheiropteris) that were recognized by previous pteridologists as a distinct group were selected by stepwise discriminant analysis. Prior to performing discriminant analyses, the data matrix was modified, i.e. characters that did not satisfy the assumption of normal distribution were transformed by taking them with the natural logarithm. The canonical discriminant analyses was performed by using the CLASSIFY procedure in SPSS/PC for Windows, release 10.0 (Anonymous, 1999). Results and Discussion Cluster Analysis (CA): The UPGMA dendrogram that constructed using GSC measure showed three discrete groups (Fig. 1) at GSC 0.75. Group 1 included Neocheiropteris palmatopedata and Group 2 comprised the four species of Platygyria. In addition, Group 3 was the largest group consisting of Lepisorus s.s., N. ensata and the two species of Paragramma. 102 CHATAN et al. At Gower similarity coefficient 0.71, these fern taxa were divided into two groups, i.e. Group 1 and a group composed of Groups 2 and 3 (Fig. 1). Group 1 is distinct from the rest mainly by the combination characters of pedatifid lamina, presence of large veins at the lamina base and lamina width (more than 120 mm) as shown in the key to the genera below. The result suggested that N. palmatopedata was far distinct from the rests while the genus Platygyria was more closely related to the genus Lepisorus and Paragramma than N. palmatopedata. In addition, genus Lepisorus, N. ensata and Paragramma are closely related to each other than the rest. Canonical Discriminant Analysis (DA): DA was divided into two analyses based on the number of prior groups obtained: 1) four groups, including Lepisorus s.s., Neocheiropteris, Paragramma and Platygyria, all of which were assigned based on previous recognized genera (such as Christ, 1905; Ching, 1940; Copeland, 1947; Pichi Sermolli, 1977; Ching and Wu, 1980; Zhang et al., 2003); and 2) three groups, including Groups 1, 2 and 3, which were obtained from CA. Overall, 26 quantitative characters were used in these analyses with a purpose to test their groupings. Fig. 1. UPGMA clustering of 487 Operational Taxonomic Units (OTUs) based on 53 quantitative and qualitative characters of Lepisorus, Paragramma, Platygyria and Neocheiropteris. Once the stepwise analysis had been performed for all four groups, the linear discriminant function classification showed that 97.3% of the specimens had been correctly classified. The nature of the differences between the entries were shown by the pooled within canonical structure wherein canonical variable 1 was 97.3% correlated with the 26 quantitative characters and explained 86.2% of the total variance, which was highly associated with three characters (Table 1). Canonical variable 2 was 81.6% correlated with the quantitative characters and explained 9.7% of the total variance, which was highly associated with four characters. Canonical variable 3 was 68.1% correlated with the quantitative characters and explained 4.2% of the total variance, which was highly associated with seven characters (Table 1). PHENETIC RELATIONSHIP BETWEEN LEPISORUS AND RELATED GENERA 103 Table 1. Pooled within canonical structure of the four priori groups (i.e. Lepisorus, Paragramma, Platygyria and Neocheiropteris) as recognized by pteridologists, results based on 26 quantitative characters (Appendix II) scored in this study. Characters in bold were selected by stepwise discriminant analysis for further use in canonical discriminant analysis. *indicates the large absolute correlation between each variable and any discriminal functions. Discriminant function Characters 1 2 3 AW .954* -.018 .007 NM -.079* .058 -.032 SPOL .055* -.012 -.038 LL -.049 .017 .034 LW -.003 .520* -.126 SL -.014 .440* .086 STL .056 .364 .014 LLST .087 .359* -.007 PHD -.086 .337* .256 STPH -.081 -.264 .201 RHDM -.048 .232 .063 RSWI -.061 .222 -.005 STD -.097 .201 .195 RSLE .034 .129 -.100 SPW .041 -.054 .041 NSSR -.091 -.055 .464* PHL -.045 .181 .390* LLLF .027 .075 .250* RHLI -.081 .135 -.218* LFPL -.026 .024 .210* SW -.010 -.036 -.192* LLLT .003 .129 -.178 LASL -.031 .148 -.164 RHSI -.020 .071 -.136 SPOW .108 -.057 .133* SPL .045 .000 .049 The stepwise analysis was carried out for the three groups, i.e. these groups were split by the UPGMA dendrogram using GSC at 0.75. The nature of the differences between the entries was shown by the pooled within the canonical structure wherein canonical variable 1 was 97.2% correlated with the 26 quantitative characters and explained 89.7% of the total variance, which was highly associated with three characters (Table 2). Canonical variable 2 was 81.6% correlated with the quantitative characters and explained 10.3% of the total variance which was highly associated with seven characters (Table 2). The linear discriminant function classification (Table 3) obtaining from the program showed that the specimens had been 100% correctly classified; obviously, therefore, this 104 CHATAN et al. Table 2. Pooled within canonical structure of three groups (i.e. Lepisorus (including Paragramma), Platygyria and Neocheiropteris) obtained from CA based on 26 quantitative characters (Appendix II). Characters in bold were selected by stepwise discriminant analysis for further use in canonical discriminant analysis. * indicates the large absolute correlation between each variable and any discriminal functions. Discriminant function Discriminant function Characters 1 2 Characters 1 2 AW .968* -.033 STPH -.069 -.258 LLLF .085 .082 PHD -.008 .235 LL -.070 .012 STD -.072 .219 SPOW .069 .022 RHDM -.014 .205 SPOL .056* .013 RSWI -.042 .159 NM -.034 .019 NSSR -.088 -.147* LFPL -.027* -.023 RHLI .013 .145 LW -.002 .503* SPW .032 -.126 SL -.014 .453* SPL .040 -.119 LASL -.030 .333 RSLE .059 .099 LLLT .018 .310* RHSI .017 .093 LLST .087 .310* PHL -.043 .092* STL .043 .306 SW -.010 .033* Table 3. Classification Function Coefficients of three groups (i.e. Lepisorus (including Paragramma), Platygyria and Neocheiropteris) obtained from CA based on the 26 quantitative characters (Appendix II). This linear discriminant function classification received from the program showed that the specimens had been 100% correctly classified. Categories Characters Lepisorus (including Paragramma) Platygyria Neocheiropteris NSSR -0.201 -0.099 -0.026 PHL -9.480 -6.281 -6.687 LW 13.926 3.554 4.198 SL 25.130 2.926 3.254 SW -8.708 -3.013 -2.182 LFPL 2.936 7.615 7.031 SPOL 0.116 0.134 0.100 AW 0.302 1.306 0.365 LLST 0.119 0.290 -1.834 LLLT 1.230 -0.967 -1.146 (Constant) -89.828 -163.867 -49.985 PHENETIC RELATIONSHIP BETWEEN LEPISORUS AND RELATED GENERA 105 function could be used for further identification of these ferns. To identify an unknown specimen, one needs to multiply each character score by its coefficient in each column, compute the total for each column, the column with the highest total is the group to which the specimen belongs. The ordination plot on the two canonical axes obtained from the four groups analysis (Fig. 2) showed that canonical axis 1 divided these plants into two main groups, one group included Lepisorus s.s., Paragramma and Neocheiropteris, and the other consisting solely of Platygyria. However, canonical axis 2 was able to separate N. palmatopedata from the rest. Therefore, these two axes could divide these ferns into three groups. Furthermore, these results were similar when the plants were divided into three groups based on the result of CA (not shown). Fig. 2. Ordination plot on the canonical axes 1 and 2 of the four priori assigned groups (Ο: Lepisorus, ▼: Paragramma, □: Platygyria, ∆: Neocheiropteris). Circumscription of Lepisorus and Paragramma As far as the taxonomic position or circumscription of the Paragramma is concerned, there are two different forms of recognition so far, i) the form that maintains them as a distinct genus (Ching, 1940; Copeland, 1947; Pichi Sermolli, 1977) and ii) the form that combines the Paragramma with Lepisorus s.s. (Holttum, 1954; Tagawa and Iwatsuki, 1989; Hennipman et al., 1990; Hovenkamp, 1998). The key characters that Copeland 106 CHATAN et al. (1947) used to distinguish Paragramma from his Pleopeltis (i.e. including Lepisorus s.s.) were the combination of its soral shape and the presence of lamina scales. In Copeland’s key to genera of Polypodiaceae, as well as in his description, he showed that Paragramma had elongated, oblong or linear-oblong sori and that its lamina was not covered by peltate scales, while his Pleopeltis generally had round or elongate sori or fused sori, but the elongate-sori species had peltate scales on the lamina. It was observed from this study that Paragramma longifolia and P. balteiformis had round sori together with elongate sori. Paragramma longifolia, however, had glabrous lamina while few clathrate scales occurred on the lamina of P. balteiformis. Moreover, both elongate sori and few scales on the lower surface of lamina could have occurred in some Lepisorus species, for example L. angustus Ching, L. subconfluens Ching and L. scolopendrium Tagawa. So, the combination of lamina scales and soral shape could not be used to separate Paragramma from Pleopeltis. Accordingly, Paragramma could not also be separated from Lepisorus by using these characters. The results of both CA and DA strongly indicated that Paragramma and Neocheiropteris ensata were not distinct from Lepisorus s.s., so the genus Paragramma should be treated as a synonym of the genus Lepisorus. Likewise, N. ensata should be treated as a species of the genus Lepisorus. Furthermore, Fraser-Jenkins (1997) noted that N. ensata is a misapplied name of N. ovata (Fée) Fras.-Jenk. Bosman et al. (1998), however, recognized N. ensata as Microsorum ensatum (Thunb.) H. Itô, but also noted that their justification was based on a single specimen from Malesia. They also added that M. ensatum is probably a hybrid between a species of Lepisorus and a true Microsorum species. The results from this study, therefore, strongly support the recognition of Tagawa and Iwatsuki (1989), Hennipman et al. (1990) and Hovenkamp (1998) that the circumscription of the genus Lepisorus must include Paragramma. In addition, the new finding is that N. ensata should be transferred to the genus Lepisorus. Circumscription of Neocheiropteris and Platygyria For Platygyria, three taxonomic positions have been recognized, i.e. combining with Lepisorus s.s. (Yu and Lin, 1997; C.R. Fraser-Jenkins, personal communication), treating it under Neocheiropteris (Ching, 1933; Hennipman et al., 1990) and maintaining the status of distinct genus (Ching and Wu, 1980; Zhang et al., 2003). Firstly, the Platygyria was proposed as a genus of Polypodiaceae by Ching and Wu in 1980 wherein the characters used to define this taxon were the globose sporangium and the very broad annulus consisting of scarcely indurate cell walls. Fraser-Jenkins (1997) had an opinion that P. variabilis should belong to Lepisorus clathratus (C.B. Clarke) Ching and the rest of Platygyia appeared to belong to Phymatopteris Pic. Serm. because according to him the type-species, Platygyia waltonii, is in fact a Phymatopteris, another genus of the PHENETIC RELATIONSHIP BETWEEN LEPISORUS AND RELATED GENERA 107 Polypodiaceae. However, the genus Phymatopteris is not recognized by Hennipman et al. (1990) and Smith et al. (2006). It was suggested that annulus characters are not constant (C.R. Fraser-Jenkins, personal communication), while Zhang et al. (2003) determined that they are rather stable. After studying Platygyria in comparison with Lepisorus, Neocheiropteris and Paragramma, it was found that the annulus characters were not only important in separating Platygyria from Neocheiropteris, but also from Lepisorus and Paragramma. However, when herbarium specimens were examined, we found that some specimens having both sporangia which were globose, having very broad annulus (≥ 105 µm) and few indurate cells of annulus (i.e. indurate cells of annulus 1-5 or less than 1/5 of annulus or absent) and sporangia which were flat or slightly flat, having narrow annulus (<100 µm) and prominent indurate cells (i.e. more than half of annulus are indurate cell). It was found from this study that these specimens were mixed with specimens of Lepisorus clathratus and were placed in the folder of Lepisorus clathratus complex. However, they should be separated from L. clathratus and put into the genus Platygyria. In addition, the position of the stomium is an important character to distinguish the Platygyria from the rest. According to Wilson (1959), the annulus was the whole ring of cells horizontally encircling the capsule and interrupted at the point of attachment to the stalk. Most ferns had a row of indurate cells for the annulus, and this row were also interrupted by thin wall cells of epistomium, stomium and hypostomium. The stomium in most ferns could occur between the epi- and hypostomium, but it could not occur on the row of indurate cells of annulus. In Platygyria, however, the annulus cells are homogeneous or slightly homogeneous, and most or all annulus cells had thin walls. For these reasons, the position of the stomium in Platygyria could not be of constant occurrence as in other ferns and can be present throughout or slightly throughout the annulus. The tuft of hairs dorsally attached to the rhizome scales has been given much weight by Ching (1933) and Tagawa and Iwatsuki (1989) as a characteristic of their Neocheiropteris s.l. Examinations of this characteristic found that these hairs could also be found in Neocheiropteris palmatopedata, N. ensata and Platygyria waltonii, but they were not found in the other Platygyria species. In addition, they could be found in some Lepisorus species, i.e. L. kawakami Tagawa, L. macrosphaerus Ching, L. marginatus Ching and L. monilisorus (Hayata) Tagawa. Thus, this characteristic could not be considered as a diagnostic characteristic of Neocheiropteris. Moreover, according to both CA and DA, Platygyria, Lepisorus s.l. and Neocheiropteris were split into three distinct groups (Figs 1 and 2). These results were supported by the recognition of Ching and Wu (1980) and Zhang et al. (2003) in maintaining Platygyria as a distinct taxon. Therefore, the characteristics of the Platygyria were globose sporangia, very broad annulus (≥ 105 µm) and few indurate cells of annulus 108 CHATAN et al. (i.e. indurate cell of annulus 1-5 or less than 1/5 of annulus or absent). In addition, the circumscription of Platygyria should include the species or specimens that have similar characters. Neocheiropteris palmatopedata, the type species and one of the two representatives of the genus Neocheiropteris in this study should be kept under Neocheiropteris. The striking characters that have never been used as key characters to distinguish it and the other taxa are pedatifid laminas and the presence of large veins at the lamina base. Also, the lamina width is between 147-376 mm while less than 100 mm lamina width found in the rest taxa. Thus the result is also supported by CA and DA. Previously, Lepisorus s.s. (Ching, 1933, 1940), Paragramma (Ching, 1940; Copeland, 1947; Pichi Sermolli, 1977) and Platygyria (Ching and Wu, 1980; Zhang et al., 2003) were recognized as separate genera by some pteridologists. Also, Neocheiropteris was recognized as a distinct genus from the genera above (Christ, 1905). The results were examined in terms of morphology and anatomy, and the two multivariate analyses of which can be proven to recognize that Platygyria was a distinct taxon from Lepisorus, Neocheiropteris and Paragramma. Moreover, N. palmatopedata should be put into a different group. On the other hand, the circumscription of Lepisorus should include N. ensata and Paragramma. This study found ten important quantitative characters that could be used for splitting Lepisorus (including N. ensata and Paragramma), N. palmatopedata (here it is recognized as a monotypic genus) and Platygyria by including the annulus width, sporangium length, length of the fertile portion of lamina, lamina width, sorus length, ratio of lamina length and lamina tip length, ratio of lamina length and stipe length, number of sclerenchyma strand in rhizome, phyllopodia length, and sorus width. Some of these characters, including annulus width and lamina width, and some useful qualitative characters i.e. lamina indentation, prominent large vein at lamina base, occurrence of indurate cells and stomium position were used to construct a key to genera as below: Key to genera 1a. Annulus width ≥ 105 µm, indurate cell of annulus 1-5 or absent, stomium not constantly positioned on annulus (rarely not as above) Platygyria 1b. Annulus width ≤ 95 µm, indurate cell are more than half of annulus cells, stomium between the thin wall epi- and hypostomium 2 2a. Lamina pedatifid, lamina width ≥ 120 mm, large vein at lamina base present Neocheiropteris 2b. Lamina margin entire or undulate, lamina width < 120 mm, large vein at lamina base absent Lepisorus (including Neocheiropteris ensata and Paragramma) PHENETIC RELATIONSHIP BETWEEN LEPISORUS AND RELATED GENERA 109 Acknowledgements The authors sincerely appreciate the efforts of anonymous reviewer who reviewed this manuscript. We are grateful to the curators or keepers of the following herbaria: BKF, BM, E, K, KUN, L and PYU, who allowed access to and facilitated the study of the herbarium specimens. Many thanks are due to Dr. M.C. Roos (L) and Dr. M.J. Zink for supplying the literatures. The first author would like to thanks Dr. Liu Ende (KUN), Dr. Xiangjingying (KUN), Prof. S.K. Wu (KUN), Dr. Zhao-Rong He (PYU), Dr. David J. Middleton (E), Dr. P. Hovenkamp (L), Dr. H.P. Nooteboom (L) and Miss Suchada Wongpakam for their help or suggestions, and the curator or keeper of TI, who gave some type-specimen images to him. This project was partially supported by the Center for Excellence in Biodiversity, Faculty of Science, Chulalongkorn University, under the Research Program on Conservation and Utilization of Biodiversity, CEB_D_9_2006, the TRF/BIOTEC Special Program for Biodiversity Research and Training, Grant T_249003, and the Commission on Higher Education, Thailand (the Cooperative Research Network - CRN). References Anonymous, 1999. SPSS for Windows release 10.0, Standard Version [Computer Program]. SPSS Inc., Chicago. Bosman, M.T.M., Hovenkamp, P.H. and Nooteboom, H.P. 1998. Microsorum. In: Kalkman, C. and Nooteboom, H.P. (eds), Flora Malesiana. Rijksherbarium/Hortus Botanicus, Leiden, the Netherlands, pp. 90-133. Ching, R.C. 1933. The studies of Chinese ferns IX. Bull. Fan. Mem. Inst. 4(3): 47-113. Ching, R.C. 1940. On natural classification of the family Polypodiaceae. Sunyatsenia 5(4): 201-270. Ching, R.C. and Wu, S.K. 1980. Platygyria Ching & S.K.Wu, a unique new genus of the Polypodiaceae from China. Acta Bot. Yunn. 2(1): 67-74. Ching, R.C., Lin, Y.X. and Wu, S.K. 1983. A taxonomic revision on Lepisorus clathratus (C.B. Clarke) Ching complex in Sino-Himalayan region. Acta Bot. Yunn. 5(1): 1-23. Christ, H. 1905. Les collections de fougeres de la Chine au Muséum d’histoire naturelle de Paris. Bull. Soc. Bot. France 52, Mém. 1(I): 1-69. Copeland, E.B. 1947. Genera Filicum. Chronica Botanica, Waltham, Massachusett, USA, pp. 1-247. Fraser-Jenkins, C.R. 1997. New Species Syndrome in Indian Pteridology and the Ferns of Nepal. International Book Distributors, Dehra Dun, India, pp. 1-403. Gower, J.C. 1971. A general coefficient of similarity and some of it properties. Biometrics 27: 857-872. Hennipman, E., Veldhoed, P. and Kramer, K.U. 1990. Polypodiaceae. In: Kubitzki, K. (ed.), The Families and Genera of Vascular Plants. 1. Springer Verlag, Berlin, pp. 203-230. Holttum, R.E. 1954. A Revised Flora of Malaya II. Ferns of Malaya. Government Printing Office, Singapore, pp. 1-653. Holmgrens, P.K. and Holmgrens, N.H. 2008. Index Herbariorum. . Retrieved on 11 December 2008. Hovenkamp, P.H. 1998. Lepisorus in Malesia. Blumea 43(1): 109-115. 110 CHATAN et al. Lin, Y.X., 2000. Polypodiaceae subfamily Lepisorioideae Ching. In: Lin, Y.X. (ed.), Flora Reipublicae Popularis Sinicae 6(2). Science Press, Beijing, pp. 32-115. Pichi Sermolli, R.E.G. 1977. Tentamen pteridophytorum genera in taxonomicum ordinem redigendi. Webbia 31(2): 313-512. Shieh, W.C., Devol, C.E. and Kuo, C.M. 1994. Polypodiaceae. In: Hsieh, C.F., Huang T.C., Keng, H., Shieh, W.C, Tsai, J.L., Hu, J.M., Shen, C.F., Yang, K.C. and Yang, S.Y. (eds), Flora of Taiwan (Pteridophyta and Gymnospermae). Vol. 1. Sandos Chromagraph Printing Company, Ltd, Taipei, pp. 469-519. Smith, A.R., Pryer, K.M., Schuettpelz, E., Korall, P., Schneider, H., and Wolf, P.G. 2006. A classification for extant ferns. Taxon 55(3): 705-310. Tagawa, M. and Iwatsuki, K. 1989. Pteridophytes. In: Smitinand, T. and Larsen, K. (eds), Flora of Thailand 3(4). Chutima Press, Bangkok, pp. 481-639. Verdcourt, B. 2001. Polypodiaceae. In: Beentje, H.J. and Smith, S.A.L. (eds), Flora of Tropical East Africa. A.A. Balkema, Rotterdam, pp. 1-37. Wilson, K.A. 1959. Sporangia of the fern genera allied with Polypodium and Vittaria. Contr. Gray Herb. 185: 97-127. Yu, S.L. and Lin, Y.X. 1997. A study on systematics of genus Lepisorus (Polypodiaceae). Acta Phytotax. Sin. 35(4): 341-347. Zhang, X.C., Liu, Q.R. and Xu, J. 2003. Systematics of Platygyria Ching & S.K.Wu (Polypodiaceae). Acta Phytotax. Sin. 41(5): 401-415. Zink, M.J. 1993. Systematics of the fern genus Lepisorus (J.Sm.) Ching (Polypodiaceae-Lepisoreae), with special reference to Africa and including and annotated list to all names published so far. PhD dissertation, Universität Zürich, Zürich, pp. 1-147. (Manuscript received 13 March 2008; revised on 17 December 2008) Appendix I. A list of representative specimens of each species examined. -Lepisorus amaurolepidus (Sledge) Bir & Trikha: Fraser-Jenkins et al. 24 (Ceylon); Jarrett 673 (India); Manickam 606 (India). -L. annuifrons (Makino) Ching: Faurie 5252 (Japan); Kano et al. 26 (Japan); Makino s.n. (Japan). -L. bampsii (Pic. Serm.) M.J. Zink (= L. excavatus Ching): Bamp 2962 (Rwanda). -L. bicolor (Takeda) Ching: Duclaux 5044 (China); Henry 2465 (China); Maxwell 94-1025 (Thailand). -L. boninensis (Christ) Ching: Tuyama 512 (Japan); Warburg s.n. (Japan). -L. clathratus (C.B. Clarke) Ching: Chola Rangle 4300 (India); Cischison183 (Afghanistan); Ludlow et al. 17223 (Bhuthan). -L. contortus (Christ) Ching: Fleming 879 (Nepal); Henry 6869 (China); Zimmerman 396 (Nepal). -L. eilophyllus (Diels) Ching: Henry 6859 (China); Purdom 90 (China); Wilson 2636 (China). -L. elongatus (Kaulf.) Ching: Gaudichaud s.n. (Sandwich Island); Hildebrand 18 (Hawaii). -L. excavatus (Bory ex Willd.) Ching: Burger 505 (Ethiopia); Ghose 39 (China); Pichi Sermolli 6793 (Ethiopia). -L. jakonensis (Blanf.) Ching (= L. pseudonudus Ching): Blanford 354 (India), s.n. (India). -L. mehrae Fraser-Jenk.: Datta 23475 (India); Steward 1494 (India). -L. kawakami (Hayata) Tagawa: Faurie s.n. (China); Tagawa 47 (China). -L. kuchenensis (Y.C. Wu) Ching: Cadiére 1126 (Indochina); Colani 2829 (Vietnam); Poilane 17045 (Vietnam). -L. lewisii (Baker) Ching: Henry 9194B (China); Shearer s.n. (China); Tsang 23481 (China). -L. loriformis (Wall. ex Mett.) Ching: C.B.Clarke 12947 (India); Fleming 1734 (Nepal), Wallich 271 (Nepal). -L. macrosphaerus (Baker) Ching: Cavalerie 3748 (China); Duclaux 3352 (China); Poilane 26824 (Vietnam). - PHENETIC RELATIONSHIP BETWEEN LEPISORUS AND RELATED GENERA 111 L. manus Hovenkamp: De Wilde & De Wilde-Duyfjes 1305 (Indonesia); Otto-Surbeck 365 (Indonesia); Surbeck 644 (Indonesia). -L. marginatus Ching: Zhang 1 (China). -L. megasorus (C.Chr.) Ching: Hancock 31 (China); Poilane 5113 (Indochina). -L. mildbraedii (Hieron.) Pic.Serm. (= L. excavatus Ching): Le Walle 1284 (Burundi), 2442 (Burundi); Taton 270 (Congo-Belge). -L. monilisorus (Hayata) Tagawa: Chang 4400 (Taiwan); Faurie 475 (China), 594 (China). -L. morisonensis (Hayata) H.Ito: Tagawa 417 (China). -L. nudus (Hook.) Ching: Ballard 1035 (Ceylon); Dharmsani 2028 (Nepal); Stewart 21047 (India). -L. obscure- venulosus (Hayata) Ching: Faurie 472 (China); Poilane 25575 (Indochina); Shimizu & Chuang 20418 (Taiwan). -L. oligolepidus (Baker) Ching: Cavalerie 34 (China); Henry 2049 (China); Matthew 31 (China). - L. onoei (Franch. & Sav.) Ching: Iwatsuki 1540 (Japan); Iwatsuki et al. 5566 (Japan); Ohba 662598 (Japan). -L. preussii (Hieron.) Pic.Serm.: Brunt 764 (Cameroon); Chapman 62 (Nigeria); Saxer 13 (Cameroon). -L. pseudonudus Ching: Luo 237(64) (China); Wilson 2633 (China). -L. pseudo-ussuriensis Tagawa: Faurie 591(China), 644 (China); Tagawa s.n. (China). -L. schraderi (Mett.) Ching: Chase 6568 (Rhodesia); Loveridge 392 (Uganda); Pichi Sermolli, P. 5141 (Tanzania). -L. scolopendrium (Ching) Mehra & Bir: Gamble 8212 (India); Hancock 104 (China); Smitinand et al. 1744 (Thailand). -L. sesquispedalis (J.Sm.) Fraser-Jenkins (= L. scolopendrium (Ching) Mehra & Bir): Chola Rangle 4399 (India); Duthie 5183 (India); Kari 176 (China). -L. subconfluens Ching: Hennipman 3141 (Thailand); Rock 8727 (China); Snitinand 4667 (Thailand). -L. sublinearis (Baker ex Takeda) Ching: Hancock 83 (China); Henry 9062A (China); Tagawa et al. 2878 (Thailand). -L. thunbergianus (Kaulf.) Ching: Cox et al. 198 (China); Taquet 3656 (Korea); Wilson 53179 (China). -L. tosaensis (Makino) H.Ito: Tagawa & Iwasuki 3716 (Japan). -L. ussuriensis (Regel & Maack) Ching: Furuse 7138 (Japan); Komrov 46 (China); Tagawa 764 (Japan). -Neocheiropteris ensata Ching: Tagawa and Iwasuki 539 (Japan); Gustav Mann. s.n. (India); Tagawa,Togashi and Kanoi s.n. (Japan). -N. palmatopedata Christ: Beauvais 830 (China); Chang 808 (China); Kokonor Tibet complex expedition 13339 (China); Qin 83 (China). -Paragramma balteiformis (Brause) Hovenkamp: Brass 23289 (Papua New Guinea), 12075 (Papua New Guinea). -P. longifolia (Blume) T. Moore: Boonkerd 1191 (Thailand); Cadière 791 (Vietnam); Edano 35625 (Philippines). -Platygyria inaequibasis Ching & S.K.Wu: Li & Wang 20658 (China); Wu et al. 75-771 (China); Zhang (Dian team) 1753 (China). -P. soulieana (Christ) X.C. Zhang & Q.R. Liu: Delavay 207/1 (China); Li 3 (China). -P. variabilis Ching & S.K.Wu: Ching 23475 (China); Chu & Feng, 747 (China); Sykes & Williams 3503 (Nepal). -P. waltonii (Ching) Ching & S.K.Wu: Littledale s.n. (China); Tibetean team 74-3626 (China); Walton s.n.(China). Appendix II. A list of 26 quantitative characters with unit or character states used in the study of Lepisorus and its related genera. Abbreviation Characters RHDM rhizome diameter in mm RHSI shortest rhizome internode length in mm RHLI longest rhizome internode length in mm NM number of meristele in rhizome NSSR number of sclerenchyma strand in rhizome RSLE rhizome scale length in mm RSWI rhizome scale width in mm STL stipe length in mm STD stipe diameter at the middle of its length in mm PHL phyllopodia length in mm PHD phyllopodia diameter at the middle of their length in mm LL lamina length in mm LW lamina width in mm 112 CHATAN et al. Abbreviation Characters LASL length of the apical sterile portion of lamina in mm SL sorus length in mm SW sorus width in mm LFPL length of the fertile portion of lamina in mm SPOL sporangium length in µm SPOW sporangium width in µm AW annulus width in µm SPL spore length in µm SPW spore width in µm STPH ratio of stipe length and phyllopodium length LLST ratio of lamina length and stipe length LLLT ratio of lamina length and lamina tip length LLLF ratio of lamina length and length of fertile portion Appendix III. A list of 27 qualitative characters with unit or character states used in the study of Lepisorus and its related genera. Abbreviation Characters RHS rhizome surface: not glaucous (0), glaucous and not glaucous (1), glaucous (2) RSA apex of rhizome scale: obtuse (0), obtuse and acute (1), acute and acuminate (2), filiform (3) RSB base of rhizome scale: obtuse and round (0), obtuse and round and cordate (1), cordate (2) RSM margin of rhizome scale: entire (0), entire, dentate and denticulate (1), dentate and denticulate (2) RSS shape of rhizome scale: lanceolate and triangular and ovate (0), circular, lanceolate, triangular and ovate (1) RSCL clathrate appearance of rhizome scale: clathrate throughout (0), center clathrate with non clathrate margin (1), center clathrate with non clathrate margin, and center opaque with clathrate or non clathrate margin (2), center opaque with clathrate and non clathate margin (3) RSOR orientation of rhizome scale: appressed (0), appressed and slightly spreading (1), slightly spreading (2), strongly spreading (3) RSCO colour of rhizome scale: one colour (0), one and two colours (1), two colours (2) RSAT attachment type of rhizome scale: all scale basifixed (0), pseudopeltate, basifixed and peltate (1), all scale peltate (2) RSUS appearance of hairs on upper surface of rhizome scale: absent (0), present (1) RSL lobe of rhizome scale: absent (0), present (1) RSIP insertion point of rhizome scale: at base and close to base more than apex (0), at base, at the middle and close to base more than apex (1) LI lamina indentation: margin entire and undulate (0), auriculate (1), hastate and pedatifid (2) LA lamina apex: acute (0), acute and acuminate (1), acute, acuminate, obtuse and round (2), acute, obtuse and round (3), acuminate (4), acuminate, obtuse and round (5), obtuse and round (6) LT lamina texture: membranaceous and chartaceous (0), membranaceous, subcoriaceous and coriaceous (1), subcoriaceous and coriaceous (2) ABL abaxial surface of lamina: lamina glabrous (0), lamina covered by few to low density of scales near the base or near midrib or on midrib (1) ADL adaxial surface of lamina: lamina glabrous (0), lamina glabrous and covered by few to moderate density of scales near lamina base or near midrib or on midrib (1) LPL longitudinal posture of lamina margin : flat (0), slightly revolute (1), strongly revolute (2) PHENETIC RELATIONSHIP BETWEEN LEPISORUS AND RELATED GENERA 113 Abbreviation Characters LV veins or lateral vein prominence on abaxial surface of lamina: inconspicuous (0), inconspicuous and conspicuous (1), conspicuous (2) LBS symmetry of lamina base: symmetric and nearly symmetric (0), present both symmetric and asymmetric base (1) SODBA sori distribution between lamina base and apex: only on upper half (0), on upper half and reaching to the lower half (1); only on lower half (2) SORN sorus row number between midrib or rachis, and the margin: one row (0), one row and more than one row (1), more than one row (2) SOPO sorus position between midrib and frond margin: only at the middle (0) at the middle to close to midrib (1); at the middle to close to the margin (2), close to midrib to close to the margin (3), only close to the midrib (4); only close to the margin (5) SOR sori orientaion when compare with the closest midrib: not oblique (0), present both oblique and not oblique sori (1), oblique (2) STOP stomium position: at the position between the thin wall epi- and hypostomium (0), not constantly positioned on annulus (1) INDC occurrence of indurate cells: more than half of annulus are indurate cells (0), indurate cell of annulus 1-5 or less than 1/5 of annulus or absent (1) BALV large vein at lamina base: absent (0), present (1) For Platygyria, three taxonomic positions have been recogniz