01649nas a2200193   4500008004100000245009000041210007000131260001200201300001200213490000700225520102500232653001501257653001201272653001401284653000901298100001401307700001801321856011601339       2002                        eng d00aPhylogeny of Isoëtes (Lycopsida): Resolving basal relationships using rbcL sequences0 aPhylogeny of Isoëtes Lycopsida Resolving basal relationships usi  c2002///  a83 - 890 v513 aThe phylogenetic relationships of Isoëtes (Isoëtaceae) were investigated by means of a cladistic analysis using plastid rbcL sequences and a representative sample of 18 species. The analysis supports a basal split in Isoëtes separating two main groups, one including aquatic species from South America (I. bradei and I. amazonica) and West Africa (I. kersii and I. schweinfurthii), and the other including aquatic, amphibious and terrestrial species representing all major continents. Higher level relationships remain unresolved, but supported groups do conflict with previous morphology-based hypotheses. Comparatively low levels of sequence divergence indicate that the use of more rapidly evolving regions will be required to resolve higher level relationships. The phylogenetically isolated nature of Isoëtes will in such analyses make standard outgroup comparisons problematic, and results presented here will in this respect prove important by providing support for choosing among alternative rooting options.10aIsoetaceae10aIsoetes10aPhylogeny10arbcL1 aRydin, C.1 aWikström, N.  uhttp://www.scopus.com/inward/record.url?eid=2-s2.0-0036254372&partnerID=40&md5=f4c2dc2699e8c72b00c4dccdb1f20c1f