Glaucium flavum, is a perennial plant in the family of Papaveraceae (Poppy family). The plant is native to from coastal northern Europe, the British Isles, around the Mediterranean and Black Sea in Europe, North Africa and Southwest Asia, in a wide range of habitats near the seas or in otherwise saline or lean soils. Naturally grows on the seashore and is never found inland. In Türkiye, Yellow Horned Poppy is naturally found at all coastal areas. The name for the genus was first described by the Scottish botanist Philip Miller; comes from the Greek word ‘glaukos‘ meaning gray green in reference to the colour of the foliage. The specific epithet ‘flavum’ given by the Austrian botanist Heinrich J. N. von Crantz, comes from the Latin word ‘flavus‘ meaning golden yellow, in reference to the flower colour. The English common name Yellow Horned Poppy comes from the narrow horn-like seed capsules that are used in dried floral arrangements. It is also called the Sea Poppy for its preference to habitats near the seas.

Glaucium flavum, is a slow growing perennial that grows up to 50-60 cm tall with mounded rosettes of thick, leathery, deeply segmented, bluish-grey leaves. The leaves are 7-20 cm long and 2-5 mm wide, coated in a layer of water-retaining wax. This plant is a perennial but is often listed as a biennial because of its short lifespan; however, it often lasts more than two years. Plant blooms the first year from seed and then reblooms in subsequent years. From early spring through midsummer on mature plants, the 5-7 cm wide bright yellow flowers rise above the foliage on branched stems. The flowers have a central tuft of orange stamens and four silky, 2 cm long petals that drop as the long-curved seedpods develop. Later it produces an upright, thin, distinctive horn shaped capsule, which is 15 cm or long. The seed pods ripen in late summer to spread their seed around the garden.

Yellow Horned Poppy grows in full sun, well drained soil, it is extremely tolerant to salt, withstand -15˚C. Propagation is done by seed. It produces an orange foul smelling sap, if cut open. All parts of the plant, particularly the roots, including the seeds, are toxic if taken by mouth, can cause a wide range of symptoms, and respiratory failure, resulting in death. Glaucine is the main alkaloid component in Glaucium flavum. Glaucine has bronchodilator and anti-inflammatory effects, and is used medically as an antitussive in some countries. Glaucine may produce side effects such as sedation, fatigue, and a hallucinogenic effect characterized by colorful visual images.

Use in Landscape: Some find Yellow Horned Poppy a bit disorderly, but it is a great addition to the natural garden where its attractive glaucous foliage with golden flowers. It naturally grows in coastal habitats on shingle banks and beaches, so it can be used any salty beaches for landscape without any problem. Also, it can be grown as a pot plant in gardens.