Rediscovery of a halophytic endemic and rare species of Portulaca (Portulacaceae) from central Argentina: morphology and its phylogenetic position

Portulaca ragonesei (Portulacaceae), an extreme halophyte species from Salina de Ambargasta (central Argentina), is here illustrated and re-described based on morphological evidence. In addition, molecular data shows that this endemic species is one of the earliest-divergent lineages of the Oleracea clade. This is a critically endangered species that can be morphologically distinguished by its sprouting geophyte habit, the linear leaves, and the presence of a constriction at the apex of the pixidium where only one seed is found.