Phylogeny of the Flaxes: Evolutionary Relationships in the Linaceae and Linum.
J. R. McDill¹, M. Repplinger², B. B. Simpson¹, J. W. Kadereit²;
¹Section of Integrative Biology and The Plant Resource Center, The University of Texas at Austin, Austin, TX, United States, ²Institut für Spezielle Botanik und Botanischer Garten, Johannes Gutenberg Universität, Mainz, Germany.
Presentation Number: 13.8.6
Keyword: Linum, Linaceae, Phylogenetics

Linaceae, best known for the useful fibers and oils from the cultivated flax, Linum usitatissimum, is a widespread family with 13 genera and 300 species, ranging from diminutive temperate annuals to woody tropical trees and climbers. The position of Linaceae in Malpighiales has been clarified in large-scale phylogenetic analyses, but relationships within the family have not been addressed. To determine the circumscription of monophyletic Linaceae and the relationships of the large, cosmopolitan genus Linum to the other temperate genera, especially the segregates from Linum, we sampled all 13 Linaceae genera and the 5 sections of Linum. Phylogenetic analyses of rbcL sequences in the context of the Malpighiales show that the tropical genera of Linaceae subfamily Hugonioideae subtend the monophyletic temperate subfamily Linoideae. Within Linoideae, analyses of trnK 3' and trnL introns, trnL-F spacer, and nuclear ITS show that Linum is not monophyletic: the blue-flowered linums are sister to the yellow-flowered linums, Hesperolinon, Sclerolinon, Radiola and Cliococca. The central Asian Tirpitzia, Reinwardtia, and Anisadenia are basal in the Linoideae.