The Portulacaceae are a family of flowering plants, comprising 115 species in a single genus Portulaca. Formerly some 20 genera with about 500 species, were placed there, but it is now restricted to encompass only one genus, the other genera being placed elsewhere. The family has been recognised by most taxonomists, and is also known as the purslane family. It has a cosmopolitan distribution, with the highest diversity in semiarid regions of the Southern Hemisphere in Africa, Australia, and South America, but with a few species also extending north into Arctic regions. The family is very similar to the Caryophyllaceae, differing in the calyx, which has only two sepals. The APG II system (2003; unchanged from the APG system of 1998) assigns it to the order Caryophyllales in the clade core eudicots. In the APG III system, several genera were moved to the Montiaceae, Didiereaceae, Anacampserotaceae and Talinaceae, thus making the family monotypic and only containing the genus Portulaca. Species The following species are accepted: Portulaca africana (Danin & H.G.Baker) Danin Portulaca almeviae Ocampo Portulaca amilis Speg. – Paraguayan purslane Portulaca anceps A.Rich. Portulaca argentinensis Speg. Portulaca aurantiaca Proctor Portulaca australis Endl. Portulaca badamica S.R.Yadav & Dalavi Portulaca bicolor F.Muell. – Australian pigweed Portulaca biloba Urb. – Cuban purslane Portulaca brevifolia Urb. Portulaca bulbifera M.G.Gilbert Portulaca californica D.Legrand Portulaca canariensis Danin & Reyes-Bet. Portulaca cardenasiana D.Legrand – Puerto Rican purslane Portulaca caulerpoides Britton & P.Wilson Portulaca centrali-africana R.E.Fr. Portulaca chacoana D.Legrand Portulaca ciferrii Chiov. Portulaca clavigera R.Geesink Portulaca colombiana D.Legrand Portulaca commutata M.G.Gilbert Portulaca confertifolia Hauman Portulaca conoidea S.M.Phillips Portulaca constricta M.G.Gilbert Portulaca conzattii P.Wilson Portulaca coralloides S.M.Phillips Portulaca cryptopetala Speg. Portulaca cubensis Britton & P.Wilson Portulaca cyclophylla F.Muell. Portulaca cypria Danin Portulaca daninii Galasso, Banfi & Soldano Portulaca decipiens Poelln. Portulaca decorticans M.G.Gilbert Portulaca dhofarica M.G.Gilbert Portulaca diegoi Mattos Portulaca digyna F.Muell. Portulaca dodomaensis M.G.Gilbert Portulaca echinosperma Hauman Portulaca edulis Danin & Bagella Portulaca elatior Mart. ex Rohrb. Portulaca elongata Rusby Portulaca eruca Hauman Portulaca erythraeae Schweinf. Portulaca fascicularis Peter Portulaca filifolia F.Muell. Portulaca filsonii J.H.Willis Portulaca fischeri Pax Portulaca fluvialis D.Legrand Portulaca foliosa Ker Gawl. Portulaca fragilis Poelln. Portulaca frieseana Poelln. Portulaca fulgens Griseb. Portulaca gilliesii Hook. Portulaca giuliettiae T.Vieira & A.A.Coelho Portulaca goiasensis T.Vieira & A.A.Coelho Portulaca gracilis Poelln. Portulaca grandiflora Hook. – moss-rose purslane Portulaca grandis Peter Portulaca granulatostellulata (Poelln.) Ricceri & Arrigoni Portulaca greenwayi M.G.Gilbert Portulaca guanajuatensis Ocampo Portulaca halimoides L. – silkcotton purslane Portulaca