Jordärtskocka, Heliantus tuberosus, is ‘Jerusalem artichoke’. The etymology is a mess.
As one can feel a similarity in structure and taste of the tuber and the artichoke bud, the plant has got part of its name from the artichoke. Artichoke comes from an arabic word, al-hursufa via Spanish and Italian. The word has been twisted and turned in many folk etymologies; in Swedish it is kronärtskocka, krona – ‘crown’ probably because of the stately flower, and ärt – ‘pea’, from the taste, the rest is unintelligible.
Swedish jordärtskocka, becomes ‘earth artichoke’ – that’s simple, much simpler than the English term: Jerusalem in this case has nothing to do with the town, instead it comes from Italian girasole ‘sunflower’.
Yes, the jordärtskocka is closely related to the sunflower, Helianthus annuus; a difference here up north is that the warm season is not long enough for them to flower, instead they proliferate by the tubers (that’s why the Latin species name is tuberosus). The plant originates from North America, where it was cultivated before the Europeans arrived.
We dug these up yesterday, very late in Spring, they have already started to grow; they are not very big, should have been better fertilised. This year we will plant a few in another place, but however careful you are when digging up the tubers, you always miss some, and in autum there will be tubers to dig up together with the potatoes we have planted there now.