While much is known on which characteristics are typical of a tree, shrub, herb or liana, we still largely ignore what changes occur at the vascular level when one growth form transitions into the other and to which pressures they respond. With this project we intend to unravel what anatomical modifications occur in the xylem and phloem, both primary and secondary, in habit transitions, how they impact or are impacted by the presence of cambial variants, and whether they are related to the occupation of new habitats (e.g., forest 🡪 savannah) or represent new niche occupation within the same habitats. With the use of well-supported phylogenies and phylogenetic comparative methods we can raise new hypothesis on xylem and phloem evolution beyond those classical that were initially proposed in the late 19th and early 20th century. Currently we have ongoing projects with Bignoniaceae, Convolvulaceae (Ipomoea), Malpighiaceae (clade Bunchosia), and Nyctaginaceae.