About

Centaurea macrocephala is a species of flowering plant in the family Asteraceae, and a member of the thistle tribe, Cardueae (Cynareae). It has many common names, including bighead knapweed, big yellow centaurea, lemon fluff, yellow bachelor's button, yellow hardhat, and Armenian basketflower.

This plant is native to the Caucasus. It is known throughout much of the world as an introduced species and sometimes a noxious weed. It is a popular garden plant, and is widely available for cultivation as an ornamental.

Where it grows

As the plant has been transported around the world for ornamental use it has taken hold as an introduced species in several areas. It is a casual garden escapee in parts of Europe and North America. It has only become a troublesome noxious weed in a few areas, notably Washington state in the United States, where it is prohibited to buy or sell the species. Its invasive nature is best seen in garden environments, where it is more aggressive than most other ornamental plants and can become a "garden thug".

Uses

This is a well-known ornamental flowering plant. It has been a garden flower for over 200 years, being introduced to the United Kingdom and United States in the early 19th century. Thomas Jefferson obtained seeds from the nurseryman Bernard McMahon and planted them at Monticello.

Other Centaurea plants

Centaurea acaulis · Akamas centaury · Centaurea alba · Centaurea ammocyanus · Rough star-thistle · Centaurea atropurpurea · Centaurea behen · Blessed Thistle · Red star-thistle · Karl-Henrikh's Centaury · Dusty miller · Centaurea collina