[Wikipedia] Southern Europe, northwest Africa, and eastward through southwes: Euphorbia lathyris, the caper spurge or paper spurge, is a species of spurge native to southern Europe (Italy, Greece, Spain, Portugal), northwest Africa, and eastward through southwest Asia to western China. (link added by Mary Ann Machi)

[pfaf.org] Toxicity: The sap contains a latex which is toxic on ingestion and highly irritant externally, causing photosensitive skin reactions and severe inflammation, especially on contact with eyes or open cuts. The toxicity can remain high even in dried plant material[200]. Prolonged and regular contact with the sap is inadvisable because of its carcinogenic nature[214]. The seed is also poisonous[76]. (link added by Mary Ann Machi)