One of those in the Mallow family removing plantain from national park (4)
I believe the answer is:
Here is my best explanation:
'one of those in the mallow family' is the definition.
I can't tell whether this definition defines the answer.
'removing plantain from national park' is the subsidiary indication.
'removing' indicates anagramming the letters (moving the letters again).
'from' suggests deleting specific letters.
'nationalpark' with 'plantain' taken out is 'oark'.
'oark' is an anagram of 'okra'.
(Other definitions for okra that I've seen before include "Lady's finger", "A vegetable", "Long green tropical vegetable", "Gumbo", "Edible seed pods", "Vegetable", "old ladies' fingers", "Bhindi or lady's finger", "Pod eaten in soups, stews etc" and "Lady's fingers; gumbo; bhindi".)