New records of the genus Orobanche L. (Orobanchaceae) to the Tunisian flora with lectotypification of the name O. rapum-genistae Thuill

Based on several field surveys and on the study of original material, we have identified three new species of Orobanche L. s.s. (Orobanchaceae) new to the flora of Tunisia. Orobanche alba Willd., O. calendulae Pomel, and O. gracilis Sm. are reported as new for the country, and the occurrence of O. rapum-genistae Thuill. is confirmed. The lectotypification of O. rapum-genistae is here proposed with a specimen housed in Genève (G). The geographical distribution of the four taxa in Tunisia is given, and details of habitats and hosts are provided. Altogether, the genus Orobanche in Tunisia now includes 18 species; a dichotomous key is proposed to facilitate the identification of these taxa.