Plant given to hothead from Eire (5)
I believe the answer is:
irish
'from eire' is the definition.
(I've seen this before)
'plant given to hothead' is the wordplay.
'plant' becomes 'iris' (type of flower).
'given to' is a charade indicator (letters next to each other).
'hothead' becomes 'h' (head letter of 'hot').
'iris'+'h'='IRISH'
(Other definitions for irish that I've seen before include "race" , "Like Wilde or Yeats" , "From Dublin maybe" , "Joyce was" , "Hi, Sir, become a national" .)