Green smoothie add-in (4)

I believe the answer is:
kale
(Other definitions for kale that I've seen before include "Crinkled-leaf cabbage" , "Cabbage variety" , "Vegetable" , "Crinkle-leaf cabbage" , "Type of cabbage" .)
I believe the answer is:
kale
(Other definitions for kale that I've seen before include "Crinkled-leaf cabbage" , "Cabbage variety" , "Vegetable" , "Crinkle-leaf cabbage" , "Type of cabbage" .)