This species has a wide Eurasian distribution; the distribution in Italy is still poorly known because of the frequent confusion with other related species: there are validated reports from Lombardy, Lazio, Molise, Sardinia and Sicily. It grows in stagnant and slowly flowing waters that are poor in nutrients, from sea level to about 1500 m. It is a characteristic species of Mediterranean temporary ponds, but in Sardinia it was found only in two sites, Paule Longa (Ghilarza) and Sos Fungarones (Olmedo). The genus name is that of a plant mentioned by Pliny and comes from the Greek 'elate' (fir), in reference to the similarity of the submerged leaves of some species to the needles of the fir tree; the species name refers to the vague resemblance to species of the genus Alsine. Flowering period: May to August.

Italian name(s): Pepe d'acqua maggiore (Italia).