Typification of three Linnaean names in the genus Euphorbia (Euphorbiaceae)

The lectotypification of four Linnaean names in the genus Euphorbia: E. exigua, E. exigua var. acuta, E. paralias, and E. segetalis is discussed. The designation of the nomenclatural types is based on the consultation of Linnaeus’s original material and the literature cited in the respective protologues. The name E. exigua had previously been “lectotypified” by Jafri & El-Gadi in 1982 on a specimen kept in LINN. However, Linnaeus cited in the protologue a specimen from the Joachim Burser Herbarium, currently preserved at UPS-BURSER. According to the ICN (International Code of Nomenclature for algae, fungi, and plants), this is a syntype which must be chosen as the lectotype. The name E. exigua var. acuta is lectotypified using a specimen preserved in the Clifford Herbarium at BM and is treated in this paper as a heterotypic synonym of E. exigua var. exigua. The name E. paralias had previously been “lectotypified” by Geltman in 2015 (repeated in 2020) on a specimen kept in S-LINN. However, this specimen is not original material for the name. The lectotype of E. paralias is designated in this paper from a specimen preserved at S-LINN according to the ICN. Finally, the name E. segetalis is lectotypified using a Morison illustration.