Michaelmas daisy, eg (5)
I believe the answer is:
aster
'michaelmas daisy eg' is the definition.
(michaelmas daisy is a kind of aster)
This is all the clue.
(Other definitions for aster that I've seen before include "Plant like a Michaelmas daisy" , "Daisy-like garden flower" , "Showy garden flower" , "Daisy-like plant" , "Stare (anag.)" .)