was published for Araliaceae by Kew Gardens. Nine species were recognized therein for Gastonia. The genus was described as "generalized, altho in details, it is quite varied". Since that time, molecular phylogenetic studies, based on DNA sequences, have shown that Gastonia was polyphyletic. These studies have shown that biogeography is strongly correlated with relationships in Araliaceae. In 2010, the genus Polyscias was expanded from about 100 species to 159. The number of species in Polyscias will be around 250 when the undescribed species are published. Six genera (Arthrophyllum, Cuphocarpus, Gastonia, Reynoldsia, Munroidendron, and Tetraplasandra) were placed in synonymy under Polyscias. In accordance with the phylogenetic studies of DNA, Polyscias was divided into 11 subgenera (Polyscias, Grotefendia, Maralia, Arthrophyllum, Cuphocarpus, Tetraplasandra, Eupteron, Sciadopanax, Tieghemopanax, Indokingia, and Palmervandenbroekia) and seven species were left incertae sedis. The nine species that had been in Gastonia went to four different subgenera of Polyscias; three species went to Grotefendia, three more to Indokingia, two to Tetraplasandra, and one to Maralia.Polyscias cutispongia, Polyscias maraisiana, and Polyscias rodriguesiana are endemic to Réunion, Mauritius, and Rodrigues, respectively. The latter two were separated from P. cutispongia in 1984. They are in Polyscias subgenus Grotefendia, which comprises 15 species, all from the Mascarene Islands. The type species for Polyscias subgenus Grotefendia is Polyscias repanda.Polyscias subgenus Grotefendia contains Polyscias cutispongia, the type species for Gastonia. If the subgenus Grotefendia were to be raised to the taxonomic rank of genus, the name Gastonia would have priority over Grotefendia, according to the ICNAFP.Polyscias crassa, Polyscias sechellarum, and Polyscias lionnetii are all from the Seychelles, with Polyscias lionnetii being very rare and restricted to the island of Mahé. These are the only species of Polyscias in the Seychelles, and together, they constitute Polyscias subgenus Indokingia. "Polyscias seychellarum" is an orthographical variant of Polyscias sechellarum. Polyscias sechellarum was divided into three varieties in 1987, but some authors have declined to recognize them until further studies can be done on this species.Polyscias duplicata (formerly Gastonia duplicata) is in Polyscias subgenus Maralia. Maralia is, by far, the largest subgenus of Polyscias, with about 115 species. Most of them, like Polyscias duplicata, are endemic to Madagascar.Polyscias serratifolia and Polyscias spectabilis are now in Polyscias subgenus Tetraplasandra. This is a wide-ranging subgenus of 21 species. Eleven species are endemic to Hawaii, and ten others are distributed in a large area that includes Malesia and extends eastward to Tahiti. References Sources