A new species of Simaba sect. Grandiflorae (Simaroubaceae) from Jalapao region, Tocantins, Brazil

Simaba tocantina, a new species of Simaroubaceae, is described and illustrated. It belongs to Simaba sect. Grandiflorae since its flowers reach 21-25 mm long and its staminal appendages are covered by intertwined trichomes forming a pseudotube around the gynoecium. Its differences from the related species in the section are pointed out herein, including a key to the five species of the group. As other cerrado members in the genus, the new species is a shrub with a thickened underground system, from which a few aerial branches develop, as well as a long, erect, showy inflorescence. It is known only by a few records from the cerrado of the Jalapao State Park in Tocantins, Brazilian Central Plateau, and its conservation status is assessed.