# Glaucium flavum

Glaucium flavum, the yellow horned poppy, yellow hornpoppy or sea poppy, is a summer flowering plant in the family Papaveraceae. It is native to Europe, Northern Africa, Macaronesia and temperate zones in Western Asia. The plant grows on the seashore and is never found inland. All parts of the plant, including the seeds, are toxic. It is classed as a noxious weed in some areas of North America, where it is an introduced species. It is grown in gardens as a short-lived perennial but usually grown as a biennial.

## Description

It has thick, leathery deeply segmented, wavy, bluish-grey leaves, which are coated in a layer of water-retaining wax. The sepal, petals and stamen have a similar structure and form to the red poppy (Papaver rhoeas), except the sepals are not hairy. It grows up to 30–90 cm (1–3 ft) tall, on branched, grey stems. It blooms in summer, between June and October. It has bright yellow or orange flowers, that are 7.5 cm (3 in) across. Later, it produces a very long, upright, thin, distinctive horn shaped capsule, which is 15–30 cm (6–12 in) long. It is divided into two chambers, which split open to reveal the seeds.

## Taxonomy

It was first published and described by Heinrich Johann Nepomuk von Crantz in 'Stirp. Austr. Fasc.' (Stirpium Austriarum) vol.2 on page 133 in 1763. The species epithet flavum is Latin for yellow and indicates its flower colour.
It is commonly known as sea-poppy, horned-poppy, and yellow horned-poppy.
G. flavum was verified by United States Department of Agriculture and the Agricultural Research Service on 25 May 1995, then updated on 9 May 2011, and is an accepted name by the Royal Horticultural Society.

## Distribution and habitat

It is native to temperate regions of North Africa, Europe and parts of Western Asia.

### Range

It is found in North Africa, within Macaronesia, Canary Islands, Algeria, Libya, Tunisia and Morocco. Within Western Asia it is found in the Caucasus, Georgia, Cyprus, Egypt (in the Sinai), Lebanon, Syria and Turkey. In eastern Europe, it is found within Ukraine. In middle Europe, it is in Belgium, Germany, Netherlands and Slovakia. In northern Europe, in Denmark, Ireland, Norway, Sweden and United Kingdom. In south-eastern Europe, within Albania, Bosnia and Herzegovina, Bulgaria, Croatia, Greece, Italy, Montenegro, Sicily and Malta, North Macedonia, Romania, and Slovenia. In southwestern Europe, it is found in France, Portugal and Spain.

### Habitat

It grows in coastal habitats on shingle banks and beaches, but can also be found on cliff tops and in sand dunes.

## Toxicity

It produces an orange foul-smelling sap, if cut open. All parts of the plant, including the seeds, are toxic, and can cause a wide range of symptoms if eaten, and respiratory failure, resulting in death.

## Culture

It is referenced in various poems.
A poppy grows upon the shore,  Bursts her twin cups in summer late: Her leaves are glaucus-green and hoar,  Her petals yellow, delicate.
She has no lovers like the red,  That dances with the noble corn: Her blossoms on the waves are shed,  Where she stands shivering and forlorn.
             Shorter Poems Robert Bridges.
Sea Poppies:
Amber husk fluted with gold, fruit on the sand marked with a rich grain,
treasure spilled near the shrub-pines to bleach on the boulders:
your stalk has caught root among wet pebbles and drift flung by the sea and grated shells and split conch-shells.
Beautiful, widespread, fire upon leaf, what meadow yields so fragrant a leaf as your bright leaf?
H.D.

## Uses

Glaucine is the main alkaloid component in Glaucium flavum. Glaucine has bronchodilator and antiinflammatory effects, acting as a PDE$_4$ inhibitor and calcium channel blocker, and is used medically as an antitussive in some countries. Glaucine may produce side effects such as sedation, fatigue, and a hallucinogenic effect characterised by colourful visual images, and as a recreational drug. For a detailed bibliography on glaucine and Glaucium flavum see: National Agricultural Library.
In the past, it was known in Hampshire, UK, as 'squatmore', and the roots were used to treat bruises, and pains in the breast, stomach and intestines.