Yellow horn poppy, sea-poppy or yellow horned poppy is a summer flowering plant, It has thick, leathery deeply segmented, wavy, bluish-grey leaves, which are coated in a layer of water-retaining wax. In the past, it was known in Hampshire, UK as ‘squatmore’, and the roots were used to treat bruises. Also pains in the breast, stomach and intestines. It produces an orange foul smelling sap, if cut open. All parts of the plant, including the seeds, are toxic if eaten.
Often this species needs to be planted just before the frost or needs a long period of cold for Stratification, so its seed dormancy can be overcome.