Glaucium flavum, or Glaucium luteum, or Glaucium flavum f. flavum is also known as the Hornpoppy, Horned Poppy, Yellow Horned Poppy, Caillichín na trá, Bruiswort, Seaside Poppy or Sea Poppy. It usually grows close to the sea therefore the common name Sea Poppy. It is part of the Papaveraceae family of plants.
This short-lived perennial is usually grown as a biennial and is native to North Africa, Macaronesia (a collection of 4 archipelagos in the Atlantic Ocean northwest of Africa), Caucasus, Europe, and Western Asia. It was first noted in 1763 by Heinrich Johann Nepomuk von Crantz (1722-1799), a physician who also was a botanist, he was born in Luxembourg and died in Austria. The name flavum from Latin meaning yellow signifies its flower color.
Glaucium flavum forms a rosette of bluish-green foliage that is deeply segmented. It has gray stems that are branched. The orangish-yellow flowers have a similar structure to the Red Poppy but the sepals are not hairy. The flowering season is in the summer continuing to early autumn.
After flowering, it produces longhorn shaped capsules with chambers full of seeds. The capsules can be as long as 30cm or 1ft. Glaucium flavum can grow up to 90cm or 3ft. Glaucium flavum plants and seeds are toxic. It is drought-resistant. It is disease-free and pest-free. Plant it in the sun in moderately fertile or even poor soil but it needs to be well-drained, located under the full sun. Usually doesn’t like to be moved around or roots disturbed.