In Siena, it’s known for its seed (5)

I believe the answer is:

anise

'it's known for its seed' is the definition.

'in siena' is the wordplay.
'siena' anagrams to 'ANISE'.
But, I am unsure how the anagram is indicated.

(Other definitions for anise that I've seen before include "Plant with aromatic seeds" , "Plant with liquorice-flavoured seeds" , "Aromatic Mediterranean plant" , "Herb with aromatic seeds" , "Plant providing flavour similar to liquorice" .)

I've seen this clue in the Evening Standard.

Want a hint initially instead of a full solution? Install my app