ABSTRACT

Ludwigia L. is the largest genus of Onagraceae, despite its representativeness in Brazil, it has been understudied, leading to misidentified specimens in herbaria. This study provides an inventory of Ludwigia species occurring in the State of Piauí. Specimens of Onagraceae were analyzed in the CSTR, HUEFS, RB, and TEPB herbaria, as well as digitized specimens available on speciesLink and Reflora. Identification was based on specialized literature. Ten species were recognized: Ludwigia affinis (DC.) H.Hara, L. elegans (Cambess.) H.Hara, L. erecta (L.) H.Hara, L. helminthorrhiza (Mart.) H.Hara, L. hyssopifolia (G. Don) Exell, L. leptocarpa (Nutt.) H.Hara, L. nervosa (Poir.) H. Hara, L. octovalvis (Jacq.) P.H.Raven, L. sedoides (Bonpl.) H.Hara, and L. tomentosa (Cambess.) H. Hara; of these, five are new records for Piauí State. Additionally, inferences about the conservation status and distribution maps of the species are presented.

Keywords:
brazilian northeast; floristic inventory; Ludwigioideae; new occurrences