Taxonomic updates to Artocarpus subgenus Pseudojaca (Moraceae), with a particular focus on the taxa in Singapore

Abstract

The breadfruit genus (Artocarpus J.R.Forst. & G.Forst., Moraceae) has 16 species in Singapore, 14 of them native. The following taxonomic changes in Artocarpus subgenus Pseudojaca Trécul, based on recent phylogenetic work, are presented with diagnostic characters. Artocarpus griffithii (King) Merr. is reinstated as distinct from A. lamellosus Blanco (which is called A. nitidus Trécul in the earlier literature), also requiring the reinstatement of the following taxa not found in Singapore: A. borneensis (Merr.) F.M.Jarrett, A. humilis Becc., A. vrieseanus Miq. var. subsessilis F.M.Jarrett and A. xanthocarpus Merr. Artocarpus dadah Miq. is reinstated as distinct from A. lacucha Roxb. ex Buch.-Ham., thereby necessitating the reinstatement of the following taxa not found in Singapore: A. fretessii Teijsm. & Binn. ex Hassk., A. ovatus Blanco, and A. vrieseanus var. refractus (Becc.) F.M.Jarrett. Artocarpus gomezianus Wall. ex Trécul is restricted to the type subspecies, and A. zeylanicus (F.M.Jarrett) E.M.Gardner & Zerega, formerly a subspecies, is elevated to species level. Thirteen lectotypes and two neotypes are designated.