Taxonomic Revisions in the Polyphyletic Genus Tabebuia s. I. (Bignoniaceae)

Recent molecular studies have shown Tabebuia to be polyphyletic, thus necessitating taxonomic revision. These revisions are made here by resurrecting two genera to contain segregate clades of Tabebuia. Roseodendron Miranda consists of the two species with spathaceous calices of similar texture to the corolla. Handroanthus Mattos comprises the principally yellow flowered species with an indumentum of hairs covering the leaves and calyx. The species of Handroanthus are also characterized by having extremely dense wood containing copious quantities of lapachol. Tabebuia is restricted to those species with white to red or rarely yellow flowers and having an indumentum of stalked or sessile lepidote scales. The following new combinations are published: Handroanthus arianeae (A. H. Gentry) S. Grose, H. billbergii (Bur. & K. Schum). S. Grose subsp. billbergii, H. billbergii subsp. ampla (A. H. Gentry) S. Grose, H. botelhensis (A. H. Gentry) S. Grose, H. bureavii (Sandwith) S. Grose, H. catarinensis (A. H. Gentry) S. Grose, H. chrysanthus (Jacq.) S. Grose subsp. chrysanthus, H. chrysanthus subsp. meridionalis (A. H. Gentry) S. Grose, H. chrysanthus subsp. pluvicolus (A. H. Gentry) S. Grose, H. coralibe (Standl.) S. Grose, H. cristatus (A. H. Gentry) S. Grose, H. guayacan (Seemann) S. Grose, H. incanus (A. H. Gentry) S. Grose, H. lapacho (K. Schum.) S. Grose, H. pulcherrimus (Sandwith) S. Grose, H. pumilus (A. H. Gentry) S. Grose, H. riodocensis (A. H. Gentry) S. Grose, H. selachidentatus (A. H. Gentry) S. Grose, H. serratifolius (Vahl) S. Grose, H. spongiosus (Rizzini) S. Grose, H. subtilis (Sprague & Sandwith) S. Grose and H. uleanus (Kraenzl.) S. Grose.