Transfer of Four New Guinean Rhus Species to Toxicodendron (Anacardiaceae)

John D. Mitchell; Susan K. Pell; Jun Wen

doi:10.3417/2025964

John D. Mitchell The New York Botanical Garden https://orcid.org/0000-0001-6934-2461
Susan K. Pell United States Botanic Garden https://orcid.org/0000-0002-7214-3225
Jun Wen National Museum of Natural History, Smithsonian Institution https://orcid.org/0000-0001-6353-522X

DOI: https://doi.org/10.3417/2025964

Keywords: New combination, nomen novum, Perrottetia, poison ivy, sumac, typification

Abstract

Four New Guinean species currently recognized in the genus Rhus L. (Anacardiaceae), R. caudata Lauterb., R. lamprocarpa Merr. & L. M. Perry, R. lenticellosa Lauterb., and R. linguata Slis, are transferred to Toxicodendron Mill. based on morphological and molecular data. All share the characteristic fruit of the poison ivy genus, clearly distinguishable by an exocarp separating from a white mesocarp that is striated with black resin canals. The inclusion of these species expands the known distribution of Toxicodendron eastward to New Guinea. The new combinations T. lamprocarpum (Merr. & L. M. Perry) J. D. Mitch., Pell & J. Wen, T. lenticellosum (Lauterb.) J. D. Mitch., Pell & J. Wen, and T. linguatum (Slis) J. D. Mitch., Pell & J. Wen are published. Toxicodendron dalyanum J. D. Mitch., Pell & J. Wen is published as a replacement name for R. caudata. A neotype is designated for R. caudata, and a lectotype for R. lenticellosum.