SIMAROUBACEAE, AN ARTIFICIAL CONSTRUCT - EVIDENCE FROM RBCL SEQUENCE VARIATION

Phylogenetic analyses of rbcL sequence data of representatives of all subfamilies indicate that Simaroubaceae sensu late is polyphyletic. It represents at least five separate lineages, only three of which (Sima rouboideae, Harrisonia, and Kirkioideae) cluster within a robust sapin dalean clade. The family is monophyletic only when comprised of member s of the subfamily Simarouboideae plus Leitneriaceae, but excluding Ha rrisonia. Harrisonia is most closely related to Cneorum and Rutaceae. Kirkioideae is distant from Simaroubaceae sensu stricto, although its affinities remain within Sapindales. The other two lineages show an af finity to taxa at some distance from Sapindales: Irvingia with a group of poorly sampled rosid I taxa comprising in part members of Linales and Malphigiales; Picramnia and Alvaradoa cluster together in an isola ted position between the broadly comprised groups of rosid I and rosid II. Support for the affinities suggested here is also evident in nonm olecular data sources: wood anatomy, pericarp structure, pollen, and p hytochemistry. The elevation of the picramnioid clade, comprising Picr amnia and Alvaradoa, to family rank is signaled, and the recognition o f Kirkiaceae and Irvingiaceae is substantiated.