Boraginaceae), and the Phylogeny of Boraginoideae

!" #$ % " "& '()*"'+ (,-./01 ** -)2'/)*) %*()'-) %%*(* 3443 Dissertation for the Degree of Doctor of Philosophy in Systematic Botany presented at Uppsala University in 2002 Abstract Långström, E. 2002. Systematics of Echiochilon and Ogastemma (Boraginaceae), and the phylogeny of Boraginoideae. Acta Univ. Ups. Comprehensive Summaries og Uppsala Disserta- tions from the Faculty of Science and Technology 693. 34 pp. Uppsala. ISBN 91-554-5257-4. Echiochilon, Ogastemma and Sericostoma are revised resulting in the recognition of 15 species of Echiochilon and one Ogastemma species. Several species are placed in synonymy and three new species are described, E. baricum, E. callianthum and E. cyananthum. The single species of Sericostoma is shown to be nested within Echiochilon. The plastid atpB gene was sequenced for Echiochilon and Ogastemma from the Old World and Antiphytum from the New World, plus for a selection of 33 other Boraginaceae taxa. They were analysed together with selected outgroup taxa to give a framework of the tribes of Boraginoi- deae. The analysis gave support for establishing the new tribe Echiochileae for Antiphytum, Echio- chilon and Ogastemma, and for merging the traditionally accepted tribe Eritrichieae with Cyno- glosseae. The ITS region was sequenced for all but one species of Echiochilon and for representa- tives of Antiphytum and Ogastemma. Phylogenetic analysis of Echiochilon revealed that the strongly zygomorphic-flowered species form a paraphyletic group. The morphological data gave results fairly congruent with the ITS phylogeny. Biogeographic interpretations of the ITS and atpB phylogenies indicated a trans-Atlantic dispersal of Antiphytum as the most plausible explanation to the Old/New World disjunction. Analyses using DIVA (Dispersal Vicariance Analysis) of the distributions of the Echiochilon species indicated an ancestor to Echiochilon with a wide distribution over northern Africa and Arabia to India. Key words: Antiphytum, Echiochilon, Ogastemma, Boraginaceae, Echiochileae, phylogeny, ITS, floral morphology, atpB, tribes, biogeography, Africa, America. Elisabeth Långström, Uppsala University, Evolutionary Biology Centre, Department of System- atic Botany, Norbyvägen 18D, SE – 752 36 Uppsala, Sweden © Elisabeth Långström 2002 ISSN 1104-232X ISBN 91-554-5257-4 Printed in Sweden by Uppsala University, Tryck & Medier, Uppsala 2002 To my son Arvid, the light of my life PREFACE This thesis is based on the following papers, which will be referred to in the text by their respective Roman numerals (I–III) I Lönn, E. 1999. Revision of the three Boraginaceae genera Echiochilon, Ogastemma and Sericostoma. Botanical Journal of the Linnean Society 130: 185–259. II Långström, E. & Chase, M. W. 2002. Tribes of Boraginoideae (Boraginaceae) and placement of Echiochilon, Ogastemma and Sericostoma: A phylogenetic analysis based on atpB plastid DNA sequence data. Accepted for publication in Plant Sys- tematics and Evolution. III Långström, E. & Oxelman, B. Phylogeny of Echiochilon (Boraginaceae) based on ITS sequences. Manuscript. Published and accepted papers are reproduced with the publishers’ kind permission. I have published my papers under two names, as Lönn when I was married and as Långström when not. All morphological work and lab work was done by myself except one sequence in paper III. I planned projects II and III and wrote the major parts of paper II and III. TABLE OF CONTENTS INTRODUCTION .................................................................................................................. 6 TAXONOMY AND MORPHOLOGY OF ECHIOCHILON AND OGASTEMMA ...... 8 PHYLOGENETIC STUDY .................................................................................................. 8 The atpB gene .............................................................................................................. 9 The ITS region ............................................................................................................ 10 PHYLOGENY OF BORAGINOIDEAE .......................................................................... 10 PHYLOGENY OF ECHIOCHILON ................................................................................. 12 Phylogeny based on molecular ITS data ............................................................... 12 Phylogeny based on morphological data .............................................................. 12 Discussion of the Echiochilon phylogenies ......................................................... 12 BIOGEOGRAPHY.............................................................................................................. 17 TAXONOMIC TREATMENT OF OGASTEMMA AND ECHIOCHILON ................. 19 Ogastemma ................................................................................................................ 19 Echiochilon ............................................................................................................... 20 Key to the species of Echiochilon and Ogastemma ........................................... 22 SVENSK SAMMANFATTNING – SWEDISH SUMMARY........................................ 26 ACKNOWLEDGEMENTS .............................................................................................. 28 REFERENCES .................................................................................................................. 30 E. Långström INTRODUCTION Plant systematists describe and name the plants of the world and unravel the phylogenetic relationship among taxa. Morphological work, molecular techniques and comput- erised mathemathical methods are commonly used to reconstruct the phylogenies of the organisms. Systematic knowledge is used also by other disciplines (all biology, e.g. ecology, pharmacognocy and conservation biology), and systematists use information from other disiplines, trying to understand how evolution operates among plants. Infor- mation from plant systematics is used, for example, when considering how to preserve genetic diversity or for getting a lead on where to look for a desired chemical substance known from another plant. Boraginaceae is a family of 2300 species with a cosmopolitan distribution. The members of Boraginaceae have many uses but none of major economic importance, except for some ornamentals, timber and dye plants. Many Boraginaceae plants have me- dicinal properties and they are used in traditional medicine for treating wounds, skin diseases, fever, chest pain etc. (Neuwinger 2000). Symphytum officinale, for example, has in Europe even been used for healing bone. Flora projects in Northeast Africa and the Arabian Peninsula (Flora of Ethiopia and Eritrea, Flora of Somalia and Flora of the Arabian peninsula and Socotra) have revealed the need for revisions of many genera in these areas. A lot of new material has been collected which has made it clear that the old classifications are outdated. One such ge- nus was Echiochilon, and the two related monotypic genera Sericostoma and Ogastemma (paper I). Echiochilon has the bulk of its species in the Horn of Africa and the Arabian Peninsula. The species of Echiochilon were until 1957 (Johnston 1957) divided in two genera, Echiochilon and Sericostoma, based on floral symmetry with the zygomorphic- flowered species referred to Echiochilon and the actinomorphic-flowered species referred to Sericostoma. The first Echiochilon species described was one of the actinomorphic-flowered species (as Heliotropium persicum Burm.f. in 1768, later transferred to Sericostoma) and the name Echiochilon was introduced in 1900 for one of the zygomorphic-flowered species. In 1957 Johnston transferred all Sericostoma species but one to Echiochilon, and in paper II the last species of Sericostoma was transferred to Echiochilon. In paper III the relationships of the Echiochilon species is investigated with morphological and molecular data. The family delimitation of Boraginaceae is controversial. Traditionally Boragina- ceae and Hydrophyllaceae were two separate families considered to be closely related. This was confirmed by broad scale molecular analyses using rbcL (e.g. Olmstead et al. 1992, Chase et al. 1993). Later studies showed that Hydrophyllaceae is nested within Boraginaceae (Olmstead et al. 1993) which was corroborated by studies of other genes (ndhF, Ferguson 1999; atpB, Långström and Chase in press). Some authors have taken the view that Boraginaceae should be further divided, recognising the different sub- families, Boraginoideae, Ehretioideae, Cordioideae, Heliotropioideae and Wellstedioi- deae, as families (e.g. Hutchinson 1969, Heywood 1993, Gottschling and Hilger 2001, 6 Systematics of Echiochilon and Ogastemma (Boraginaceae), and the phylogeny of Boraginoideae Gottschling et al. 2001). There has been much controversy at the tribal level within Boraginoideae as well (e.g. Popov 1953, Riedl 1967, 1968, 1997, Al-Shehbaz 1991, Popova and Zemskova 1995, Retief and Van Wyk 1997) Much work has been done in palynology (e.g. Erdtman 1966, Nowicke and Ridgeway 1973, Sahay 1979, Díez and Valdés 1991, El-Ghazaly 1991, 1995, Perveen at al. 1995, Scheel et al. 1996) and fruit morphology and gynoecial development (e.g. Hil- ger 1985) to improve the knowledge of Boraginaceae and to give a clearer picture of the tribal relationships in Boraginoideae. The biotechnological methodology has given new tools for easing the task of inferring relationships among taxa. Echiochilon and its close relatives have always

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