kale (n.)

"cabbage," a dialectal survival of Middle English col, from late Old English cawel, or perhaps from or influenced by cognate Old Norse kal. Both words are from Latin caulis "stem, stalk" (which in Vulgar Latin replaced brassica as the usual word for "cabbage"), from Proto-Italic *kauli- "stalk," from PIE root *(s)kehuli- "stem of a plant, stalk" (source also of Old Irish cual "faggot, bundle of sticks," Greek kaulos "stem, stalk, pole," Armenian c'awl "stalk, straw," Old Prussian kaulan, Lithuanian káulas "bone").

Latin caulis "cabbage" is the source also of Italian cavolo, Spanish col, Old French chol, French chou; it also was borrowed elsewhere in Germanic, for example Swedish kål, Danish kaal, German Kohl, Dutch kool.

variety of cabbage in which the young inflorescence forms a fleshy white head, 1590s, originally cole florye, from Italian cavoli fiori "flowered cabbage," plural of cavolo "cabbage" + fiore "flower" (from Latin flora, from PIE root *bhel- (3) "to thrive, bloom").

First element is from Latin caulis "cabbage" (originally "stem, stalk;" see cole (n.1) ) which was borrowed into Germanic and is the source of the cole in cole-slaw and of Scottish kale. The front end of the word was re-Latinized from 18c.; the back end was influenced by flower (n.). The boxer's cauliflower ear, swollen and deformed by blunt trauma, is from 1907.