You can think of artichoke as one tight green bud made of thick leaves packed one over another, sitting on top of a tall thistle. Nothing about it is open yet. To eat it you take it apart slowly, leaf by leaf, until the soft middle is all that is left. That picture — a layered green head of a plant, and the dull grey-green of its outer leaves — is what the other uses of the name hang on.
The packet's Wiktionary etymology traces the word from Arabic al-ḵuršūf through Andalusian Arabic, Old Spanish alcarchofa, Occitan artichaut and Lombard articioch into English — a borrowed sound, reshaped at every step, which is why the English spelling looks like art + choke by accident.
依照本次提供的維基詞典字源，這個字從阿拉伯文 al-ḵuršūf 出發，經過安達魯西亞阿拉伯語、古西班牙文 alcarchofa、奧克語 artichaut、北義大利的 articioch，才進到英文。一路上只是聲音被借來借去、每一站都被改一點，所以今天的拼法看起來像 art 加 choke，其實只是巧合。
Wiktionary etymology supplied in this packet (source_ref kaikki:3f6f69a190036ae4:261616323)
Three branches
吃花苞的那一種
這一族就是核心畫面本身：那顆層層疊疊、要一片片剝開來吃的綠色花苞。
noun · B1
A round green vegetable that is really the unopened flower bud of a tall thistle plant. Its thick leaves lie one over another like petals; you pull them off, eat the soft base of each one, and then eat the tender middle.
朝鮮薊
借用同一個名字的根莖菜
這一族跟核心畫面對不太上：它吃的是地下的根，不是花苞。可以想成有人把一個現成的菜名借過來，用在另一種也被當成同類蔬菜的植物上，於是一個名字底下住了兩種東西。
noun · B2
A different plant, also called an artichoke, that is grown for the lumpy root under the ground. The root looks like a small, knobbly potato, and it is cooked and eaten as a vegetable.
菊芋（洋薑）
從外皮長出來的顏色名
英文常把植物的名字拿來當顏色的名字。這一族就是從核心畫面的外層葉子取色：那種偏暗、帶灰的綠。
noun · C1
A dull, soft green colour, like the outside of the vegetable. You meet it mainly as the name of a colour, on paint charts, cloth samples, and lists of colours you can choose from.
朝鮮薊綠（灰灰的暗綠色）