Are all thistles edible?

Are all thistles edible? Or rather, are any thistles poisonous? TIA.

All thistles belong to the same family as sunflowers, which has no poisonous plants. At the very least, this means no thistle is poisonous. Edible is another matter of course, since being able to eat something doesn't mean we gain food value from it worthy of the effort. Still, thistle is indeed also edible in all the many forms. Purple thistle, sow thistle, etc. Make sure to pick the young and tender portions of course. Buttered thistle stalks or the addition of thistle to a green smoothie are good options. If you find one with large enough unopened flower buds, maybe try to get the choke out and use it like an artichoke. Fair warning that most thistles have a slightly bitter or sour flavor to them, though it isn't too strong for most people to enjoy as far as I know. Also, always try a little at first to gauge your own body reaction to the stuff.

D. Logan wrote:All thistles belong to the same family as sunflowers, which has no poisonous plants. At the very least, this means no thistle is poisonous. Edible is another matter of course, since being able to eat something doesn't mean we gain food value from it worthy of the effort. Still, thistle is indeed also edible in all the many forms. Purple thistle, sow thistle, etc. Make sure to pick the young and tender portions of course. Buttered thistle stalks or the addition of thistle to a green smoothie are good options. If you find one with large enough unopened flower buds, maybe try to get the choke out and use it like an artichoke. Fair warning that most thistles have a slightly bitter or sour flavor to them, though it isn't too strong for most people to enjoy as far as I know. Also, always try a little at first to gauge your own body reaction to the stuff.

Thanks for the comment.

I ate the stem of 2 very young thistle plants. Crunched like celery; I guess the taste, to me, was reminiscent of celery, too.

Cardoons are in the same family and get used for their stems. The flavor of any given one is going to probably differ by species, growing conditions and genetics.

Funny, just had a conversation with an herbalist friend about the cow thistle overtaking my garden bed- I ended up harvesting all of the roots and made a tincture adding in some burdock and dandelion roots for a liver tonic... I've read Milk thistle is great for liver support and all thistle has some kind of tonic effect on the liver . My friend added that she never has a problem with invasives like thistle cause she's always eating them before they can take over.... The roots didn't seem bitter so I'm thinking those could be cooked up like burdock as a root veggie as well...

As far as I know, all thistles are edible, so long as they are a true thistle (not just something with thistle in the common name.) However, all members of the sunflower family are NOT edible, including the toxic Senecio glabellus.

Milk Thistle (Silybum marianum) found Its way into my main garden a few years ago.
It is a prolific mother...
I find the stalks of the plants (before flowering)  to be succulent and agreeable as a raw snack, just like the mountain gorillas do.
It is a bit tricky peeling them as the spines on these are big and mean, but me and the gorillas don't mind.
I also have collected many seeds.  I cut off the flower heads after they ripen, but before the seeds scatter.
They are supposedly a Liver-regenerating medicine.

They make a great Bee-plant, and Ground cover..... with intense management requirements if you don't want a field of giant stabby thistles.

P.S.  I often find oodles of slugs hiding around the base of these plants during the heat of the day, if you are looking for them.

Wow! A ten year old thread in need of an update. 1st, not all thistles are in the same family (nor are they in the sunflower sub-genus helianthus). Thistels are in the overall plant family of Asteraceae  (which covers about 45% of all plants (or Trachiophytes/Angiosperms if we want to get sciency). Asteraceae and are NOT all edible (Eg. Arnica monatana). The subfamily for sunflowers Hilianthus might have no toxic plants, I'm not sure, but it's not a thistle plants family.

YES - There is some thing like a thistle which is not edible:
Mexican poppy, flowering thistle, cardo, cardosanto, Argemone mexicana in the Poppy family (Papaveraceae). If it's not yet in flower you might think it's a young yummy thistle... think again!  It's poisonous and if it wasn't for the poppy-flower-top I might casualty consume it --- loosing the symetry of my shinbones -- along with other damages as a result of its injestion.

There are actualy a few families of thistles; they are usually in the Cardueae tribe: Cardoon, Carduus, Silybum, Cynara, and Cursium. (Notice the mexican poppy above has a similar name "Cardosanto" even though it is in a different -- non-cardueae (thistles) -- family.

Centuria also has some vicious looking thistle-heads (though many of them are more gentile knappweed basketflowers [not listed here amoungst these excellent thistlate-morphology examples]):
Centaurea eriophora; Centaurea benedicta; Centaurea iberica; Centaurea solstitialis – yellow starthistle; Centaurea calcitrapa -- purple starthistle; Centaurea hyalolepis; etc..

Then you have your wild lettuce lookalikes which can be spiney like thistles, but are usually only a novice or child's mistake; as most adults would recognize thistles as being sturdy and hardy, while; wild-lettuces are soft thin limp easy wilters. I personally have heard of only one toxic-lookalike to     ☠ wild lettuces: Packera; which luckily, does not have a thistle like appearance. So, if you are foraging wild lettuce, stay away from Packera glabella!

If you are foraging thistles, stay away from Argemone mexicana!
It grows over the entier Eastern-Half of North America from Mexico and Arizona, all the way to the East-Coast and up through Canada's Manitoba and Ontario:
☠ [url=https://plants.sc.egov.usda.gov/plant-profile/ARME4] Argemone mexicana L.
Mexican pricklypoppy (From Canada to Mexico)[/url].
☠ [url=https://plants.sc.egov.usda.gov/plant-profile/AROC2] Argemone ochroleuca Sweet
pale Mexican pricklypoppy (Mx, AZ (US))[/url].