In article , Alan Gould
writes
I have always thought of Globe Artichokes, Cynara scolymus and Cardoon,
Cynara cardunculus as edible relatives of the common garden thistle,
Cirsium vulgare. They are in the compositae family, but none of the five
varieties of Cynara listed in Plantfinder have 'thistle' in their name.
What all of those plants share is vigour and hardiness, welcome enough
in cropping, but less so in decorative gardening.

Most of the plants called thistles belong to a sub-group classified as
Cardueae, which also includes Cardoons, Cornflowers, Knapweeds, et alia.
Sow-thistles are an exception; they are related to Dandelions, Lettuces,
Hawkweeds et al (Lactuceae).
--
Stewart Robert Hinsley