Southwest Desert Flora

Portulacaceae or Purslane Family has undergone recent taxonomic changes reducing the family to 1 species, the Portulaca. Purslanes are also known as Moss Roses.

Portulacaceae is a very small family of flowering plants as note above with only 1 genus, Portulaca. Portulaca has 19 species. Classification structures were revised after recent molecular based plant taxonomy research ([1] APGIII, 2009). However, many botanical floral authorities have not yet reflected the changes from this current research. At this time, until our next revision Southwest Desert Flora includes 10 genera with over 250 species in Portulacaceae.

Members of Portulacaceae include tropical and subtropical (temperate) soft shrubs (sub-shrubs) and forbs or herbs. Species may be annual, biennial or perennial. This family is cosmopolitan in distribution with high densities in semiarid Africa, Australia and North and South America. 10 genera with more than 160 accepted taxa are found throughout North America with high densities in the northwest United States.

Common characteristics or North and South American species include; succulent or fleshy leaves and stems; leaves opposite or alternate, margins entire; inflorescences axillary or terminal, cymose, racemose, paniculate or umbellate; flowers usually radially symmetrical; no true petals, 2 to 6 or 9 sepals resembling petals, the sepals enclosed by 2 green bracteoles that look like sepals; fruits are capsular.

Species of economic importance; some species are grown for their flowers, (Portulaca and Claytonia virginica –Spring Beauty); other species are popular in rock gardens such as Lewisia, Talinum and Calandrinia. Common Purslane (Portulaca oleracea is an edible succulent plant that is also an invasive weed in some areas. Other Portulaca species are used as food plants by the larvae of some Lepidoptera (Moths & Butterflies) species.

Portulaca molokiniensis is a non-woody spreading purslane endemic to Hawaii and federally listed as an endangered species.

In North America, USDA Plants.gov also lists 10 genera with 168 accepted for Portulacaceae. The Plant List includes 10 plant genera with 258 are accepted species names.

In North America the largest genera with approximate number of species are; Claytonia 28 species, Lewisia 20 species, Portulaca 19 species, Phemeranthus 17 species and Cictanthe 11 species.