Blue thistle is a beautiful flowering plant that is often spotted in gardens and meadows. This stunning perennial has a distinctive blue hue and is known for its spiky, thorny appearance. Some of the synonyms for blue thistle include sea holly, blue devil, and Eryngium. These names are often used interchangeably to describe this plant and can be found in various regions of the world. Sea holly is a popular synonym for blue thistle in Europe, while in North America, the term blue devil is more commonly used. Whatever name you choose to call it, blue thistle remains a striking addition to any garden or floral arrangement.