Glaucium, commonly known as horned poppies, is a genus of roughly 25 species of annual, biennial, and perennial herbaceous plants belonging to the family Papaveraceae, in the order Ranunculales. The genus was formally described by Philip Miller in 1754 in his Gardeners Dictionary (4th edition), and the name derives from the Greek glaukos (grey-green), alluding to the characteristically glaucous, blue-grey foliage.
Plants are lactiferous, exuding milky or coloured latex when cut. Stems are erect or ascending, terete (cylindrical in cross-section), and may be glabrous or villous. The basal leaves are petiolate with pinnatifid blades; the cauline leaves are alternate and sessile, clasping the stem at their cordate base. Flowers are large and solitary, borne on long peduncles; the two sepals are caducous and the four petals are convolute in bud, ranging in colour from yellow and golden-orange to red. Stamens are numerous.
The genus takes its common name from its most distinctive feature: the fruit is an elongated, terete capsule that tapers to a horn-like or trident-like apex, splitting into two narrow segments at maturity. Seeds are numerous, ovoid-reniform with an alveolate seed coat.
The genus is native to Europe, north Africa, and southwest and central Asia. Species are particularly associated with open, disturbed, or saline habitats, most notably beaches and coastal shingle, salt pans, and rocky slopes. Glaucium flavum (yellow horned poppy) is the most widespread and well-known species, a familiar plant of European and Mediterranean shorelines.
Etymology
The genus name Glaucium was coined by Philip Miller in 1754 and derives from the Greek glaukos (γλαυκός), meaning grey-green or sea-green, referring to the glaucous, bluish-grey colouring of the foliage that characterises many species. The common name "horned poppy" refers to the long, horn-like seed capsule.
Distribution
Glaucium is native to Europe, north Africa, and southwest and central Asia. Species are most frequently found in open, disturbed, or saline habitats: coastal shingle and sandy beaches, salt pans, dry rocky slopes, and roadsides. Glaucium flavum has become naturalised beyond its native range on coasts in parts of the Americas and Australia.
Ecology
Species of Glaucium characteristically colonise open, saline, or disturbed ground. They are frequent on coastal shingle and sand, salt pans, and unstable rocky slopes where competition from other vegetation is low. The milky latex present in all tissues is thought to deter herbivores. Flowers are pollinated by bees and other insects attracted to the large, brightly coloured petals.
