Lycoris insularis (Amaryllidaceae), a new species from eastern China revealed by morphological and molecular evidence

Lycoris insularis S.Y.Zhang & J.W.Shao, a new fertile diploid species from coastal provinces in eastern China is described. This new species is most similar to L. sprengeri in morphology and has been misidentified as the latter for a long time. However, it can be distinguished from the latter by the relatively longer perianth tube (1.5‒2.5 cm vs. less than 1.3 cm), a characteristic that was overlooked before. Phylogenetic analysis, based on complete plastid genome, showed that L. insularis is not genetically related to L. sprengeri in the genus. The former was a sister group of L. sanguinea, while the latter was closely related to L. longituba and L. chinensis and they were respectively located on different clades that were separated at the base of the phylogenetic tree. The chromosome number of L. insularis is 2n = 22. At present, as the new species is relatively widely distributed and the wild population can normally reproduce by seeds, we evaluate it as LC (Least Concern) according to criteria of the IUCN Red List.