Author: Jan Scholten
In the first version of the Plant theory, Cactaceae was placed in Subphase 4 in Portulacales in Phase 1.
Cactaceae is not treated as a whole family, but split into 4 Subfamilies in Plant theory 2: Echinocactoideae, Phyllocactoideae, Opuntioideae and Cereoideae.
Botany: genera 87; ± 2000; spiny succulents; stem spherical, column like, green, not woody; branches are like warts or spines or thorns; leaves are bristles, suppressed; growth is slow, in the form of continuous, watery swelling in mucilage, derived from cellulose instead of wood; flowers burst out, abruptly, abundant, often red, strong scent, once in so many years, short lived, lasting a few hours; fruit edible, watery, spherical congestion; wax on the surface; flowers without clear sepals, stamens many; carpel hypogenous.
Content: malic acid, tartaric acid, oxalic acid, citric acid.
Nyffeler, Reto & Eggli, Urs; A farewell to dated ideas and concepts – molecular phylogenetics and a revised suprageneric classification of the family Cactaceae; Zurich Open Repository and Archive; 2010.