Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 1401 Spikemoss patterns Systematics and historical biogeography of Selaginellaceae STINA WESTSTRAND ACTA UNIVERSITATIS UPSALIENSIS ISSN 1651-6214 ISBN 978-91-554-9647-0 UPPSALA urn:nbn:se:uu:diva-300734 2016 Dissertation presented at Uppsala University to be publicly examined in Zootissalen, Evolutionsbiologiskt centrum, Villavägen 9, Uppsala, Friday, 30 September 2016 at 09:15 for the degree of Doctor of Philosophy. The examination will be conducted in English. Faculty examiner: Professor Michael J. Donoghue (Department of Ecology and Evolutionary Biology, Yale University). Abstract Weststrand, S. 2016. Spikemoss patterns. Systematics and historical biogeography of Selaginellaceae. (Mosslummermönster. Systematik och historisk biogeografi hos Selaginellaceae). Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 1401. 50 pp. Uppsala: Acta Universitatis Upsaliensis. ISBN 978-91-554-9647-0. Selaginellaceae, spikemosses, is a heterosporous plant family belonging to the lycophytes. With an estimated age of some 350 million years, the family is historically important as one of the oldest known groups of vascular plants. Selaginellaceae is herbaceous with a worldwide distribution. However, the majority of the ca. 750 species in the single genus Selaginella are found in the tropics and subtropics. This thesis aims at elucidating the systematics and historical biogeography of Selaginellaceae. The evolutionary relationships of the family were inferred from DNA sequence data (plastid and single-copy nuclear) of one-third of the species richness in the group. Attention was paid to cover the previously undersampled taxonomic, morphological, and geographical diversity. Morphological features were studied and mapped onto the phylogeny. The results show an overall well-supported phylogeny and even more complex morphological patterns than previously reported. Despite this, many clades can be distinguished by unique suites of morphological features. With the phylogeny as a basis, together with the thorough morphological studies, a new subgeneric classification with seven subgenera, representing strongly supported monophyletic groups, is presented for Selaginella. By mainly using gross morphological features, easily studied by the naked eye or with a hand lens, the intention is that the classification should be useful to a broader audience. During the work with species determinations, it was revealed that the correct name for an endemic Madagascan Selaginella species is S. pectinata Spring, not S. polymorpha Badré as previously proposed. The robust phylogeny of Selaginellaceae allowed for a historical biogeographical analysis of the group. A time-calibrated phylogeny, together with extant species distribution data, formed the basis. The results show pre-Pangean diversification patterns, Gondwanan vicariance, and more recent Cenozoic long-distance dispersals. The many inferred transoceanic dispersals during the last 50 million years are surprising considering Selaginella’s large megaspores that are thought to have a negative effect on dispersal. In conclusion, this thesis presents a well-founded hypothesis of the evolutionary history of Selaginellaceae including its phylogeny, morphology, and historical biogeography. The thesis forms a firm basis for further studies on Selaginellaceae in particular, and gives us a better understanding of early land plant evolution in general. Keywords: classification, historical biogeography, lycophytes, nomenclature, phylogeny, Selaginella, Selaginellaceae, systematics Stina Weststrand, Department of Organismal Biology, Systematic Biology, Norbyv. 18 D, Uppsala University, SE-75236 Uppsala, Sweden. © Stina Weststrand 2016 ISSN 1651-6214 ISBN 978-91-554-9647-0 urn:nbn:se:uu:diva-300734 (http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-300734) Till farmor Maj-Lis som visade mig naturen. Cover: “Spikemoss pattern”, by S. Weststrand List of papers This thesis is based on the following papers, which are referred to in the text by their Roman numerals. I Weststrand, S., Korall, P. Phylogeny of Selaginellaceae: There is value in morphology after all! Submitted to American Journal of Botany. II Weststrand, S., Korall, P. A subgeneric classification of Selaginella (Selaginellaceae). Submitted to American Journal of Botany. III Smith, A.R., Weststrand, S., Korall, P. 2016. Selaginella pectinata resurrected: The correct name for an unusual endemic spikemoss from Madagascar. American Fern Journal 106: 131–134. IV Weststrand, S., Korall, P. Historical biogeography of the heterospor- ous Selaginellaceae: A tale of pre-Pangean diversifications, Gond- wanan vicariance and Cenozoic long-distance dispersals. Manu- script. Paper III was reproduced with kind permission from the publisher. Note. To make clear that the nomenclatural novelties in Paper II are not val- idly published in this thesis, references to the place of publication of basio- nyms or replaced synonyms have been omitted. Contents Preface ............................................................................................................. 9 1. Introduction .............................................................................................. 11 1.1 Systematics ....................................................................................... 11 1.2 Historical biogeography .................................................................... 14 1.3 Selaginellaceae .................................................................................. 15 1.3.1 Morphology and reproduction ................................................... 18 1.3.2 Systematics ................................................................................ 20 1.3.3 Why study Selaginellaceae? ...................................................... 21 2. Aims ......................................................................................................... 23 3. Materials and methods ............................................................................. 24 3.1 Studies of organisms ......................................................................... 24 3.2 Phylogenetic analyses ....................................................................... 26 3.3 Classification .................................................................................... 27 3.4 Historical biogeography .................................................................... 27 4. Results and discussion ............................................................................. 29 4.1 Paper I and II: Phylogeny and subgeneric classification of Selaginella ........................................................................................ 29 4.2 Paper III: Selaginella pectinata resurrected ...................................... 32 4.3 Paper IV: Historical biogeography of Selaginella ............................ 32 5. Concluding remarks ................................................................................. 34 6. Svensk sammanfattning ........................................................................... 35 6.1 Jättekort ............................................................................................. 35 6.2 Kort ................................................................................................... 35 6.3 Lång .................................................................................................. 36 6.3.1 Systematik ................................................................................. 36 6.3.2 Mosslumrar ............................................................................... 37 6.3.3 Avhandlingens fyra artiklar ....................................................... 39 7. Acknowledgements .................................................................................. 42 8. References ................................................................................................ 46 Abbreviations DNA deoxyribonucleic acid ICN International Code of Nomenclature for algae, fungi, and plants Ma million years ago nom. nov. nomen novum (new name) PCR polymerase chain reaction sp./spp. species (singular/plural) sp. nov. species nova (new species) subg. subgenus Preface During the last years I have been doing genealogy research. Not on my own family though, but rather on the plant family Selaginellaceae, spikemosses. I have been digging into the long history of these plants, a history starting some 350 million years ago in a world that looked very different to the world we see today. It has been challenging, but most of all fascinating to follow these plants from present to past, and back again. The work has involved several different activities, all grading into each other, within the broad field of plant systematics: field work, molecular lab work, morphological studies, phylogenetic analyses, taxonomy, nomenclature, and historical biogeograph- ical analyses. In this thesis, I present my work in four papers, all describing different aspects of the evolutionary patterns of spikemosses. 9 1. Introduction Nature can appear as an indistinguishable green mass, or it can be a place with well-known and named companions. Systematics provides us with the names, the structure, and the history of the organisms around us. For me, there is an intrinsic worth in knowing what I see when I go outside; it makes for richer and happier walks. In this section I will give you