Boraginales

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Boraginales is a taxon at the rank of order in the asterid group of flowering plants. The order includes Boraginaceae and related families.

Boraginales is recognized in neither of two major classification systems, the Cronquist system and the APG II system, but has been recognized in some recent references. The circumscription of Boraginales is essentially identical to the circumscription of Boraginaceae sensu APG. The APG system takes a broad view of Boraginaceae, including within it the traditionally recognized families Hydrophyllaceae and Lennoaceae based on recent molecular phylogenies that show that Boraginaceae as traditionally defined is paraphyletic with respect to these two families. APG includes Boraginaceae in the Euasterid clade but this family is otherwise unplaced; its precise relationship to other families in the Euasterid group remains unclear.

In the Cronquist system, Boraginaceae (including Cordiaceae, Ehretiaceae, and Heliotropiaceae) and Lennoaceae were placed in Lamiales, and Hydrophyllaceae in Solanales.

In some recent publications, Boraginaceae sensu APG is split into several families: Boraginaceae s.s., Cordiaceae, Ehretiaceae, Heliotropiaceae, and Lennoaceae and these families comprise the Boraginales.

[edit] References

• Diane, N., H. Förther, and H. H. Hilger. 2002. A systematic analysis of Heliotropium, Tournefortia, and allied taxa of the Heliotropiaceae (Boraginales) based on ITS1 sequences and morphological data. American Journal of Botany 89: 287-295 (online abstract here).
• Gottschling, M., H. H. Hilger 1, M. Wolf 2, N. Diane. 2001. Secondary Structure of the ITS1 Transcript and its Application in a Reconstruction of the Phylogeny of Boraginales. Plant Biology (Stuttgart) 3: 629-636 (abstract online here)