Plant having medicinal properties — easy to understand (6)
I believe the answer is:
simple
'easy to understand' is the definition.
(I've seen this before)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for simple that I've seen before include "Easily understood" , "Easy; plain" , "Easy or uncomplicated" , "Plant with medicinal properties" , "Impels to be plain" .)