Portulaca, Sp. Pl. 1: 445. 1753 sec. Nyffeler & Eggli (2010a)
- Type: Portulaca oleracea
- =Sedopsis, Consp. Fl. Angol. 1: 116. 1937 syn. sec. Nyffeler & Eggli (2010a)
- Type: Sedopsis sedoides
Although the circumscription of the genus has been relatively stable, the infrageneric classification remains controversial. Previous proposals (von Poellnitz 1934; Legrand 1958; Geesink 1969) are only in part consistent with the results of a recent phylogenetic analysis (Ocampo & Columbus 2012). The genus is monophyletic and has two main lineages: one whose members have opposite leaves (OL clade) and that are distributed in Africa, Asia, and Australia (except P. quadrifida L., which is a pantropical weed), and a second one whose species have alternate to subopposite leaves (AL clade) and are more widespread and originated in the New World. These major clades and their subclades have anatomical and morphological features (Ocampo & Columbus 2012; Ocampo & al. 2013) that will be used to amend the classification of Portulaca.