Thistle is the common name of a polyphyletic group of flowering plants characterised by leaves with sharp spines on the margins, mostly in the plant family Asteraceae.

The thistle, in particular Onopordum acanthium (the cotton thistle or Scotch thistle), is the national flower of Scotland, and is featured in many Scottish symbols and logos. Legend has it that a Viking attacker stepped on one at night and cried out, so alerting the defenders of a Scottish castle.

Genera in the Asteraceae with the word thistle often used in their common names include:

• Arctium – Burdock
• Carduus – Thistle
• Carlina – Carline thistle
• Centaurea – Star thistle
• Cicerbita – Sow thistle
• Cirsium – Thistle
• Cnicus – Blessed thistle
• Cynara – Artichokes, Cardoon thistle
• Echinops – Globethistle
• Notobasis – Syrian thistle
• Onopordum – Cotton thistle, also known as Scotch thistle
• Scolymus – Golden thistle or oyster thistle
• Silybum – Milk thistle
• Sonchus – Sow thistle

Plants in families other than Asteraceae which are sometimes called thistle include:

• Salsola – Saltwort, tumbleweed or Russian thistle (family Amaranthaceae)

Asteraceae | Scottish cultural icons

Disteln | Cardo (planta) | Chardon | Kardono | קוץ | Distel | Tistlar