Systematics, phylogeny and biogeography of Juncaginaceae Dissertation zur Erlangung des Grades „Doktor der Naturwissenschaften“ am Fachbereich Biologie der Johannes Gutenberg‐Universität Mainz Sabine von Mering geb. in Erfurt Mainz, Juni 2013 Dekan: 1. Berichterstatter: 2. Berichterstatter: Tag der mündlichen Prüfung: Triglochin maritima L. Saltmarsh in Denmark (Photo: SvM). “For there are some plants which cannot live except in wet; and again these are distinguished from one another by their fondness for different kinds of wetness; so that some grow in marshes, others in lakes, others in rivers, others even in the sea […]. Some are water plants to the extent of being submerged, while some project a little from the water; of some again the roots and a small part of the stem are under the water, but the rest of the body is altogether above it.” Theophrastus (370‐c. 285 B.C.) on aquatic plants in Enquiry into Plants (Historia Plantarum) TABLE OF CONTENTS INTRODUCTION 1 CHAPTER 1: Phylogeny, systematics, and recircumscription of Juncaginaceae – a cosmopolitan wetland family 7 CHAPTER 2: Phylogeny, biogeography and evolution of Triglochin L. (Juncaginaceae) – morphological diversification is linked to habitat shifts rather than to genetic diversification 25 CHAPTER 3: Revision of the Mediterranean and southern African Triglochin bulbosa complex (Juncaginaceae) 51 CHAPTER 4: Tetroncium and its only species T. magellanicum (Juncaginaceae): distribution, ecology and lectotypification 91 CHAPTER 5: Morphology of Maundia supports its isolated phylogenetic position in the early‐divergent monocot order Alismatales 103 CONCLUSIONS AND OUTLOOK 141 REFERENCES 143 APPENDICES 169 Appendix 1. List of accession (Chapter 1) Appendix 2. Voucher information (Chapter 2) Appendix 3. PCR information (Chapter 2) Appendix 4. List of studied specimens of Tetroncium magellancium Willd. (Chapter 4) Appendix 5. List of studied specimens of Maundia triglochinoides F.Muell. (Chapter 5) Appendix 6. Identification keys for Triglochin in Europe SUMMARY 189 ZUSAMMENFASSUNG 191 LEBENSLAUF ACKNOWLEDGEMENTS Publications arising from this thesis Chapter 1 of this thesis has been published in the peer‐review proceedings of the Monocots IV conference (Copenhagen, 2008): von Mering S. & Kadereit J. W. 2010: Phylogeny, systematics and recircumscription of Juncaginaceae – a cosmopolitan wetland family. – Pp. 55–79 in: Seberg O., Petersen G., Barfod A. S. & Davis J. I. (ed.), Diversity, phylogeny, and evolution in the monocotyledons – Proceedings of the Fourth International Conference on the Comparative Biology of the Monocotyledons and the Fifth International Symposium on Grass Systematics and Evolution. – Aarhus: Aarhus University Press. Chapter 2 of this thesis will be submitted to Molecular Phylogenetics and Evolution: von Mering S. & Kadereit J. W. Phylogeny, biogeography and evolution of Triglochin L. (Juncaginaceae) – morphological diversification is linked to habitat shifts rather than to genetic diversification. Chapter 3 of this thesis has been published in the Edinburgh Journal of Botany: Köcke A. V.*, von Mering S.*, Mucina L. & Kadereit J. W. 2010: Revision of the Mediterranean and southern African Triglochin bulbosa complex (Juncaginaceae). – Edinburgh Journal of Botany 67: 353–398. DOI: 10.1017/S0960428610000041. *These authors contributed equally to this publication. Chapter 4 of this thesis has been published in Willdenowia: von Mering S. 2013: Tetroncium and its only species T. magellanicum (Juncaginaceae): distribution, ecology and lectotypification. – Willdenowia 43: 13–24. DOI: 10.3372/wi.43. 43102. Chapter 5 of this thesis will be published in the Botanical Journal of the Linnean Society: Sokoloff, D. D., von Mering, S.*, Jacobs, S. W. L. & Remizowa, M. V. 2013 (in press): Flower structure of Maundia supports its isolated phylogenetic position in the early‐divergent monocot order Alismatales. – Bot. J. Linn. Soc. * SvM conducted morphological studies on herbarium material of Maundia and related taxa, gathered characters and literature information for Maundia and related taxa, and worked on the manuscript. Introduction Introduction The monocot order Alismatales is a cosmopolitan and highly diverse group comprising 13 (APG III 2009) or 14 families with about 166 genera and ~4500 species (Stevens 2001+; Table 1 in Chapter 1). It forms a well supported monophyletic clade (APG II 2003, APG III 2009, Soltis et al. 2005 and references therein) and the current circumscription includes well‐known groups such as the species‐rich and highly diverse Arum family (Araceae; e.g., Cabrera et al. 2008, Cusimano et al. 2011) as well as all marine flowering plants (seagrasses; e.g., den Hartog 1970, Green & Short 2003). Molecular phylogenetic studies have shown that Araceae are sister to all remaining families of the order, and within the latter group Tofieldiaceae are sister to the so‐called ‘core Alismatales’ (e.g., Les et al. 1997, Chase et al. 2006, Iles et al. 2013, Les & Tippery 2013). ‘Core Alismatales’ (e.g., Iles et al. 2013), approximately corresponding to the traditional order Helobiae (Engler 1909), is a morphologically highly diverse monophyletic group of aquatic and wetland plants found in all regions of the world. Core Alismatales can be divided into two informal groups based on floral character‐ istics: a “petaloid” and a “tepaloid” clade (Posluszny & Charlton 1993). While petaloid alismatids comprise the three families Hydrocharitaceae, Butomaceae, and Alismataceae (incl. Limnochari‐ taceae), tepaloid alismatids comprise the following eight families: Scheuchzeriaceae, Apono‐ getonaceae, Juncaginaceae, Posidoniaceae, Cymodoceaceae, Ruppiaceae, Potamogetonaceae, and Zosteraceae. As an early‐diverging monocot lineage, Alismatales are one key to the understanding of monocot evolution. Several studies of members of Alismatales have concentrated on comparative flower morphology and development (e.g., Posluszny & Charlton 1993, Posluszny et al. 2000, Remizowa et al. 2012b). However, some taxa have been overlooked by researchers and very little information about their biology is available in the literature. Among those poorly known taxa is the small arrowgrass family Juncaginaceae Rich., a family of annual or perennial grass‐like herbs characterised by basal, sheathing leaves and spike‐like inflorescences (Fig. 1) and underground storage organs such as bulbs, rhizomes, stolons, or tuberous roots. The family Juncaginaceae was established at the beginning of the 19th century when Louis Claude Marie Richard used the name “Juncagines” and gave the following short description plus a French translation of it: “Juncagines. Caps 2. Sperma s. Akenium: Sem. erectum. Embryo perispermi‐ cus, orthotropus, brachypodus.” (Richard 1808). Some years later, Richard listed the following genera comprising “Juncagineae”: Lilaea, Cathanthes [a synonym of Tetroncium], Triglochin, Scheuchzeria (Richard 1815). Juncaginaceae is a conserved name (nomen conservandum, nom. cons.). Circum‐ scription of the family and delimitation of genera have changed considerably since Richard’s times. More details on the history of classification are given in Chapter 1 (see also Table 1 in Chapter 1). The last comprehensive study of the family dates back to the beginning of the 20th century (Buchenau 1903). Few broader studies focussing on members of the family were published afterwards; publications were mostly restricted to regional studies (e.g., Markgraf 1981, Haynes 2004) or focussing on one or few taxa (e.g., Davy & Bisphop 1991). Notable exceptions are the revision of the tuberous‐rooted Triglochin species (Aston 1993, 1995) and the recent treatment for the Flora of Australia (Aston 2011) covering a major part of the family. 1 Introduction The number of accepted genera in Juncaginaceae has varied between three and five (e.g., Dahlgren et al. 1985, Takhtajan 1997, Haynes et al. 1998) and species numbers range from 12 to 15 (e.g., Haynes et al. 1998, Stevens 2001+, Mabberley 2008). However, these data are based on limited information and considerably underestimate the real number of species. Recent treatments have shown that the number of recognised species exceeds 30 (e.g., Köcke et al. 2010; Aston 1993, 1995, 2011). The family Juncaginaceae has an almost cosmopolitan distribution, with a notable gap in large parts of the tropics (for a distribution map see Fig. 1 in Chapter 1). Australia is the centre of species diversity with about 26 species in 3 genera (Aston 2011). Australian taxa include a group of annual Triglochin species and the Triglochin procera complex [Cycnogeton] (Aston 2011). Further species are native to the southern hemisphere: several taxa of the Triglochin bulbosa complex are endemic to South Africa (see Chapter 3; Fig. 1), and the monotypic Tetroncium is restricted to southern South America (see Chapter 4; Fig. 1). While some species are widespread in temperate or cooler regions of both hemispheres (e.g., T. palustris, T. maritima) others are restricted to small areas (e.g., T. gaspensis, T. buchenaui). Despite its small size, the family shows considerable ecological diversity. Members of Juncaginaceae are wind‐pollinated herbs which can be found in freshwater wetlands (slow‐flowing rivers, bogs, fens), in brackish water (e.g., estuaries), and in coastal salt marshes. Some taxa inhabit only seasonally wet terrestrial sites such as vernal pools or inland salt pans (e.g., annual species of Triglochin, T. bulbosa L. subspp.). Species of the T. procera complex (Cycnogeton)