This annual plant with a Mediterranean origin has now become almost cosmopolitan, and is present, with three subspecies, in all regions of Italy (as an ephemeral weed in Valle d'Aosta). It grows in ruderal pioneer vegetation, along the streets, in the cracks of paving stones, on sandy to silty-clay soils that sometimes are poor in calcium and always dry in summer, from sea level to about 600 m (in Sicily up to1000 m). The species is rare in the outer belt of the Sardinian temporary ponds, in contact with ruderal vegetation. The genus name in Greek means 'with many fruits'; the species name, deriving from Greek as well, means 'four-leaved', referring to the leaves that are arranged in whorls of 4. Flowering period: March to August.

Italian name(s): Erba migliarina (Toscana, Val di Chiana), Erba pixa (Liguria, Savona), Erba piza (Liguria, Savona), Erba savona (Piemonte), Erva turca nostrana (Sicilia), Falsa erba turca (Puglia, Lecce), Migliarina (Toscana, Val di Chiana), Migliarina a 4 foglie (Italia), Policarpo tetrafillo (Italia), Poligonu (Sicilia), Savona (Piemonte), Semolaja (Toscana).