A small family comprising two genera and 16 species occurring in tropical America, from southeastern United States to South America (Medina 2009). Traditionally, the family has been included in Phytolaccaceae s.l., but its position as an independent lineage has been well-supported by several molecular phylogenetic studies (Hilu & al. 2003; Schäferhoff & al. 2009; Brockington & al. 2009, 2011), which also showed that the family is more closely related to the Amaranthaceae/Chenopodiaceae clade rather than to Phytolaccaceae. Achatocarpaceae are characterised by having unisexual flowers, the gynoecium with two connate carpels, unilocular ovaries with two styles and a single ovule, berrylike fruits and pollen with obscure pores (Martínez-García 1985; Lipscomb 2003).
Achatocarpaceae , Nat. Pflanzenfam. ed. 2. 16c: 174. 1934, nom. cons., sec. APG III (2009)
- Type: Achatocarpus