National emblems not that prevalent until Middle Ages, ultimately (8)
I believe the answer is:
thistles
'national emblems' is the definition.
Although both the answer and definition are plural nouns, I can't understand how one could define the other.
'not that prevalent until middle ages ultimately' is the wordplay.
'not that' becomes 'this' (this one as opposed to that one).
'ultimately' indicates one should take the final letters.
The last letters of 'prevalent until middle ages' are 'tles'.
'this'+'tles'='THISTLES'
Can you help me to learn more?
(Other definitions for thistles that I've seen before include "Weeds with prickly-edged leaves" , "One of these plants is a Scottish emblem" , "Lists the strange weeds" , "The weeds have prickly leaves" , "Scottish emblems" .)