Worry about a medicinal wildflower (6)
I believe the answer is:
yarrow
'medicinal wildflower' is the definition.
The answer and definition can be both plants as well as being singular nouns.
Maybe you can see a link between them that I can't see?
'worry about a' is the wordplay.
'about' indicates anagramming the letters.
'worry' mixed up with 'a' gives 'YARROW'.
Can you help me to learn more?
(Other definitions for yarrow that I've seen before include "bloomer" , "Aromatic wild flower" , "This herb is strangely a worry" , "Herb; a worry (anag.)" , "Wild aromatic plant" .)