Alfavaca de Cobra (Parietaria officinalis)

A perennial plant, with sometimes woody stems at the base and ovate or lanceolate leaves, attenuated or rounded at the base, pubescent. It is common on walls, rocks, and stony places, and contains a remarkable amount of potassium nitrate. The infusion of the tender leaves and stems of alfavaca is widely used in Madeira to combat blood flows resulting from hemorrhoidal ailments.