<p><i>Echiochilon</i>, <i>Ogastemma</i> and <i>Sericostoma</i> are revised resulting in the recognition of 15 species of <i>Echiochilon</i> and one <i>Ogastemma</i> species. Several species are placed in synonymy and three new species are described, <i>E. baricum</i>, <i>E. callianthum</i> and <i>E. cyananthum</i>. The single species of <i>Sericostoma</i> is shown to be nested within <i>Echiochilon</i>.</p><p>The plastid <i>atpB</i> gene was sequenced for <i>Echiochilon</i> and <i>Ogastemma</i> from the Old World and <i>Antiphytum</i> 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 Boraginoideae. The analysis gave support for establishing the new tribe Echiochileae for <i>Antiphytum</i>, <i>Echiochilon</i> and <i>Ogastemma</i>, and for merging the traditionally accepted tribe Eritrichieae with Cynoglosseae. The ITS region was sequenced for all but one species of <i>Echiochilon</i> and for representatives of <i>Antiphytum</i> and <i>Ogastemma</i>. 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.</p><p>Biogeographic interpretations of the ITS and <i>atpB</i> phylogenies indicated a trans-Atlantic dispersal of <i>Antiphytum</i> as the most plausible explanation to the Old/New World disjunction. Analyses using DIVA (Dispersal Vicariance Analysis) of the distributions of the <i>Echiochilon</i> species indicated an ancestor to <i>Echiochilon</i> with a wide distribution over northern Africa and Arabia to India.</p>
| Identifer | oai:union.ndltd.org:UPSALLA/oai:DiVA.org:uu-1863 |
| Date | January 2002 |
| Creators | Långström, Elisabeth |
| Publisher | Uppsala University, Department of Systematic Botany, Uppsala : Acta Universitatis Upsaliensis |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Doctoral thesis, comprehensive summary, text |
| Relation | Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, 1104-232X ; 693 |
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