This annual plant with a strictly Mediterranean distribution is present in all regions of Italy south of the Po River. It grows in uncultivated, arid grasslands, in ruderal sites, on rooftops, and as a weed in crops, below the lower montane belt, with optimum in the Mediterranean belt; in Italy it behaves as a plant of ancient introduction (archaeophyte), often linked to pastoral activity. The species is sporadic in the outer belt of the Sardinian temporary ponds, in contact with dry grasslands and garrigue vegetation. The genus name derives from the Greek 'hypo' (below) and 'choeros' (pig) with the meaning of 'food for pigs'; the species name, from the Greek 'ákyron' (straw, scale) and 'phorein' (to bear), refers to the presence of small bristles on the receptacle. Flowering period: February to July.

Italian name(s): Costolina annuale (Italia), Ipocheride annuale (Italia).