Author: Jan Scholten
Botany: ± 24 genera; ± 150 species; trees, shrubs and lianas; tropics; some epiphytic.
Icacinaceae is a family that is difficult to define in taxonomy. It was circumscribed quite broadly. In 2001 Icacinaceae was found to be polyphyletic, one of the most unnatural assemblages of disparate groups, like Flacourtiaceae. Formerly Icacinaceae have been included in Olacaceae, Santalales, Celastrales, Thelaes or Cornales.
In the Apg3 classification Icacinaceae is placed in Lamiidae. Icacinaceae was split into four families in three different orders: Icacinaceae sensu stricto, which is connected to Garryales, Pennantiaceae placed in Apiales, Stemonuraceae and Cardiopteridaceae placed in Aquifoliales.
Metteniusaceae and Oncothecaceae are closely related to Icacinaceae.
In the Plant theory Icacinaceae is tentatively placed in Cornales, due to its relationships with Garryales and Cornales and being diverse and difficult to define and place. Icacinaceae is placed in Subphase 7, due to being epiphytic and its similarity with Olacaceae, Santalales.
Metteniusaceae: 1 genus, Metteniusa; combination of exstipulate, entire leaves and pentalacunar nodes; flowers, petals are spreading and hairy adaxially and each long, locellate and sometimes bright orange anther theca becomes broadly recurved in a semicircle; locelli in four rows, opening separately; gynoecium is paracarpous; placentation is parietal; Metteniusa fits quite comfortably into Cardiopteridaceae, without Icacinaceae; similar to Oncothecaceae; flowers of Metteniusa suggest Cornales; ovary is superior; South America.
Oncothecaceae: 1 genus, Oncotheca; New Caledonia.
Genera: Alsodeiopsis; Casimirella; Chlamydocarya; Desmostachys; Hosiea; Icacina; Iodes; Lavigeria; Leretia; Mappia; Mappianthus; Merrilliodendron; Miquelia; Natsiatopsis; Natsiatum; Nothapodytes; Phytocrene; Pittosporopsis; Pleurisanthes; Polycephalium; Polyporandra; Pyrenacantha; Rhyticaryum; Sarcostigma; Sleumeria.
Uncertain: Stachyanthus; Cassinopsis; Emmotum; Oecopetalum; Ottoschulzia; Poraqueiba; Calatola; Platea; Apodytes; Rhaphiostylis.