Buchnera nordestina (Orobanchaceae), an overlooked new species from Northeast Brazil, with an updated identification key for Buchnera of Brazil

ABSTRACT

A new species of Buchnera (Orobanchaceae) from Northeast Brazil is described and illustrated. Buchnera nordestina was first collected by Dr. Francisco Freire Allemão e Cysneiro ca. 160 years ago and remained undescribed until now. We provide notes on morphology, geographic distribution, and conservation status of the new species. Additionally, we present an updated identification key to all species of Buchnera from Brazil. Buchnera nordestina is characterized by long bracts that are usually two times longer than the calyx tube and by the presence of axillary brachyblasts, both of which are unique features within the genus. The new species occurs in restinga and cerrado vegetation in the Brazilian states of Ceará, Maranhão, and Piauí, and is assessed as Endangered (EN).

Keywords: Brazil; Buchnera; Ceará; cerrado; hemiparasitic; Maranhão; Orobanchaceae; Piauí; restinga; taxonomy