Euphorbia hyberna, commonly known as Irish spurge or hybernal spurge, is a perennial wildflower native to western Europe, with its strongest natural strongholds in Ireland and parts of southwestern Britain. It is recognized by its upright stems and vivid, chartreuse-yellow bracts that appear in spring, giving the plant its luminous, almost lantern-like look. Its name hyberna reflects its close association with Ireland (Hibernia in Latin). Unlike most spurges, it prefers damp, shaded woodland slopes, where it forms scattered colonies. Historically, its toxic milky sap was used as a folk remedy and occasionally as a fish poison—practices long abandoned due to its caustic nature.