Open Access Open Access  Restricted Access Subscription or Fee Access


New species and records in the fern genus Didymoglossum for the flora of Seychelles, with notes on the Southeast Asian D. motleyi complex (Hymenophyllaceae)



The fern flora of the Seychelles archipelago remains relatively poorly known. Recent projects involving the development of the Seychelles National Herbarium and study of key biodiversity areas have resulted in extensive explorations of the ferns on the granitic islands. Historical literature, newly collected specimens and older collections have been revised for the fern family Hymenophyllaceae as a prelude for a fern checklist, resulting in several discoveries. In Didymoglossum, specimens were found with a very unusual character: exsert sori. Revision of the specimens, including phylogenetic analyses, revealed that these belong to two distinct species: Didymoglossum beccarianum comb. nov. (until now only known from Southeast Asia) and a new species endemic to Seychelles, which is described as D. beaverianum below. The exact identity of the Southeast Asian species required to review a complex of species previously considered synonymous to D. motleyi. As a result, we propose a taxonomic hypothesis where Didymoglossum motleyi is in fact known from the type only (from Borneo); D. beccarianum includes the synonyms Trichomanes cognatum, T. sayeri and T. minutissimum and is widely distributed from Seychelles to the western Pacific Ocean and finally Didymoglossum (Trichomanes) cultratum comb. nov., which is maintained as a separate species (endemic to Fiji and known from the type only). We conclude by emphasizing the main diagnostic characters in this complex of species, including characters that have been neglected in the past.


Exsert sori, pteridophytes, submontane ravine forest, western Indian Ocean, Pteridophytes

Full Text:



Australian Biological Resources Study (1998) Flora of Australia. Volume 48: Ferns, gymnosperms and allied groups. CSIRO Publishing, xxi + 766 pp.

Baker, J.G. (1879) On a collection of ferns gathered in the Fiji islands by Mr. Horne, F.L.S. The Journal of Botany 17: 292–300.

Baker, J.G. (1891) A summary of the new ferns which have been discovered or described since 1874. Annals of Botany 5: 181–222.

Bauret, L., Grall, A., Senterre, B., Rouhan, G., Hennequin, S., Ebihara, A. & Dubuisson, J.-Y. (2015) New circumscription of Trichomanes cupressoides Desvaux (Hymenophyllaceae), an endemic filmy fern from Seychelles (Indian Ocean), and new insights into the genus Abrodictyum C.Presl in western Indian Ocean. Phytotaxa 202: 1–14.

Beddome, R.H. (1866) British India. Being figures and descriptions of ferns from all parts of British India (exclusive of those figured in “The ferns of Southern India and Ceylon”). Gantz Brothers, Madras, 345 pp.

Beddome, R.H. (1892) Handbook to the ferns of British India, Ceylon and the Malay peninsula; with supplement. Calcutta, W.Thacker, Spink, London, 638 pp.

Boufford, D.E., Hsieh, C.-F., Huang, T.-C., Kuoh, C.-S., Ohashi, H., Peng, C.-I., Tsai, J.-L. & Yang, K.-C. (2003) Flora of Taiwan. Second edition, Department of Botany, NTU, Taipei.

Brownlie, G. (1977) The pteridophyte flora of Fiji. In: Cramer, J. (Ed.) Beihefte zur Nova Hedwigia, Heft 55. Vaduz, 397 pp.

Brownsey, P.J. & Perrie, L.R. (2011) A revised checklist of Fijian ferns and lycophytes. Telopea 13(3): 513–562.

Byng, J.W. & Christenhusz, M.J.M. (2016) The number of known plants species in the world and its annual increase. Phytotaxa 261: 201–217.

Cesati, V.d. (1876) Felci e specie nei gruppi affini raccolte a Borneo dal signor Odoardo Beccari. .Atti dell’ accademia delle scienze fisiche e matematica 7: 8, t. 1, f. 2, 1–37.

Cesati, V.d. (1877) Prospetto delle felci raccolte dal Signor O. Beccari nella Polinesia durante il suo secundo viaggio di esplorazione in que’mari. Rendiconti della Accademia Nazionale delle Scienze Detta dei XL : Memorie di Scienze Fisiche e Naturali 16: 23–31.

Chandra, S., Fraser-Jenkins, C.R., Kumari, A. & Srivastava, A. (2008) A summary of the status of threatened pteridophytes of India. Taiwania 53: 170–209.

Chase, M.W. & Hills, H.H. (1991) Silica gel: an ideal material for field preservation of leaf samples for DNA studies. Taxon 40: 215–220.

Christenhusz, M.J.M. & Chase, M.W. (2014) Trends and concepts in fern classification. Annals of Botany 113: 571–594.

Christensen, C. (1906) Index filicum. Copenhagen.

Copeland, E.B. (1933) Trichomanes. Philippine Journal of Science 51: 119–280.

Copeland, E.B. (1938) Genera Hymenophyllacearum. Philippine Journal of Science 67: 1–110.

Croxall, J.P. (1986) Microgonium (Hymenophyllaceae) in Malesia, with special reference to Peninsular Malaysia. Kew Bulletin 41: 519–531.

Dallwitz, M.J., Paine, T.A. & Zurcher, E.J. (1993) User’s guide to the DELTA system: a general system for processing taxonomic descriptions. 4th edition. Available from: (accessed 1 January 2017)

Desvaux, N.A. (1827) Prodrome. De la famille des fougères. Mémoires de la Société linnéenne de Paris 6: 171–337.

Dubuisson, J.Y., Rouhan, G., Gralla, A., Hennequin, S., Senterre, B., Pynee, K. & Ebihara, A. (2013) New insights into the systematics and evolution of the filmy fern genus Crepidomanes (Hymenophyllaceae) in the Mascarene Archipelago with a focus on dwarf species. Acta Botanica Gallica 160: 173–194.

Ebihara, A., Dubuisson, J.Y., Iwatsuki, K., Hennequin, S. & Ito, M. (2006) A taxonomic revision of Hymenophyllaceae. Blumea 51: 221–280.

Edgar, R.C. (2004) MUSCLE: multiple sequence alignment with high accuracy and high throughput. Nucleic Acids Research 32: 1792–1797.

Fosberg, F.R. (1950) Notes on Micronesian Pteridophyta. American Fern Journal 40: 132–147.

Fosberg, F.R. & Sachet, M.-H. (1981) Nomenclatural Notes on Micronesian Ferns. American Fern Journal 71: 82–84.

Holttum, R.E. (1954) Revised flora of Malaya. Vol. II Ferns of Malaya. Govt. Printing Office, Singapore, 643 pp.

Hooker, W.J. & Hooker, J.D. (1894) Icones plantarum 23: t. 2229.

Huelsenbeck, J.P. & Ronquist, F. (2001) MrBayes: Bayesian inference of phylogeny. Biometrics 17: 754–755.

Kornas, J. (1994) Filmy ferns (Hymenophyllaceae) of Central Africa (Zaire, Rwanda, Burundi). 2. Trichomanes (excl. subgen. Microgonium). Fragmenta Floristica et Geobotanica 39: 33–75.

Kuhn, F.A.M. (1879) Cryptogamae vasculares. In: Ascherson, F.P.A. (Ed.) Von der Decken’s Reisen in Ost-Afrika in 1851–1861, Botany 3. Leipzig, pp. 1–91, 5 plates.

Linné, C. (1753) Species plantarum. Vol. 2. L. Salvius, Stockholm, 640 pp.

Liu, J.X., Zhang, Q.Y., Ebihara, A. & Iwatsuki, K. (2013) Hymenophyllaceae. In: Wu, Z.Y., Raven, P.H. & Hong, D.Y. (Eds.) Flora of China, Vols. 2–3 (Pteridophytes). Missouri Botanical Garden Press, Science Press, St. Louis, Beijing, pp. 93–109.

Morton, C.V. (1968) The genera, subgenera, and sections of the Hymenophyllaceae. Contributions from the United States National Herbarium 38: 153–214.

Nadeaud, J. (1873) Énumération des plantes indigènes de l’Ile de Tahiti. Librairie de la Société Botanique de France, Paris.

Nakaike, T. (1975) Enumeratio pteridophytarum Japonicum, Filicales. 375 pp.

Nakamura, T. & Matsumoto, S. (2008) Illustrated flora of ferns and fern allies of South Pacific islands. National Museum of Nature and Science, Tokai University Press, Tokai, Japan, 295 pp.

Nylander, J.A.A. (2004) MrModeltest, version 3. Distributed by the author, Uppsala.

Presl, K.B. (1843) Hymenophyllaceae. Eine botanische Abhandlung. G. Haase, Prague, 264 pp.

Rambaut, A. & Drummond, A.J. (2007) Tracer v1.5. Available from: (accessed 1 January 2017)

Ronquist, F. & Huelsenbeck, J.P. (2003) MRBAYES 3: Bayesian phylogenetic inference under mixed models. Bioinformatics 19: 1572–1574.

Schuettpelz, E. & Pryer, K.M. (2007) Fern phylogeny inferred from 400 leptosporangiate species and three plastid genes. Taxon 56: 1037–1050.

Senterre, B., Henriette, E., Chong-Seng, L., Gerlach, J., Mougal, J. & Rocamora, G. (2013) Seychelles Key Biodiversity Areas—Output 6: Patterns of conservation value in the inner islands. Consultancy Report, Ministry of Environment-UNDP-GEF project, Victoria, Seychelles, 65 pp.

Senterre, B., Rouhan, G., Fabre, I., Morel, C. & Christenhusz, M.J.M. (2014) Revision of the fern family Marattiaceae in the Seychelles with two new species and a discussion of the African Ptisana fraxinea complex. Phytotaxa 158: 57–75.

Senterre, B. & Wagner, M. (2014) Mapping Seychelles habitat-types on Mahé, Praslin, Silhouette, La Digue and Curieuse. Consultancy Report, Government of Seychelles, United Nations Development Programme, Victoria, Seychelles, 119 pp.

Shaffer-Fehre, M. (2006) A revised handbook to the flora of Ceylon. Volume XV, Part A: Ferns and fern-allies. Science Publishers, Amrind Publishing Company Private Limited, New Delhi, 334 pp.

Smith, J.E. (1793) Tentamen botanicum de Filicum generibus dorsiferarum. Mémoires de l’Académie Royale des Sciences (Turin) 5: 401–422.

Tagawa, M. & Iwatsuki, K. (1979) Hymenophyllaceae. In: Smitinand, T. & Larsen, K. (Eds.) Flora of Thailand. Vol. 3 Pteridophytes, part one. Tistr Press, Bangkok, pp. 68–100.

Tardieu-Blot, M.-L. (1939) Cryptogames vasculaires. In: Lecomte, H. (Ed.) Flore générale de l’Indo-Chine. Vol. 7 (2). Masson, Paris.

Tardieu-Blot, M.-L. (1953) Les Pteridophytes de l ’Afrique intertropicale française. Mémoires de l’Institut Français d’Afrique Noire 28: 1–241.

Tardieu-Blot, M.-L. (1964) Ptéridophytes. In: Aubréville, A. (Ed.) Flore du Cameroun. Muséum National d’Histoire Naturelle, Laboratoire de Phanérogamie, Paris, 371 pp.

Taton, A. (1946) Révision des Hyménophyllacées au Congo Belge. Bulletin de la Société Royale de Botanique de Belgique 78: 5–42.

van Alderwerelt van Rosenburgh, C.R.W.K. (1908) Malayan ferns: handbook to the determination of the ferns of the Malayan Islands (incl. those of the Malay Peninsula, the Philippines and New Guinea). The Department of Agriculture Netherlands India, Jakarta, 1002 pp.

van Alderwerelt van Rosenburgh, C.R.W.K. (1916) The Amboina Pteridophyta collected by C.B. Robinson. Philippine Journal of Science 11: 101–124.

van den Bosch, R.B. (1861a) Hymenophyllaceae Javanicae. Koninklijke Nederlandse Akademie van Wetenschappen, Amsterdam.

van den Bosch, R.B. (1861b) Hymenophyllaceae novas, synopseos supplementum. Nederlandsch Kruidkundig Archief 5 2: 135–185.

von Mueller, F. (1889) Second systematic census. Australian plants. Chronologic, literary and geographic annotations. Part I. Vasculares. McCarron, Bird & Co., printed for the Victorian Government, Melbourne, 244 pp.

Willdenow, C.L. (1810) Species plantarum editio quarta, Nauk, Berlin, 542 pp.


  • There are currently no refbacks.

ISSN 1179-3155 (print); ISSN 1179-3163 (online)

Published by Magnolia Press, Auckland, New Zealand