Spikey Garden Plant, Usually Unwanted
Puzzle 9 of Christmas Carols Piece of Cake Pack
Question is: Spikey Garden Plant, Usually Unwanted
and the answer is: THISTLE
Word Meaning:
THISTLE — Any of several perennial composite plants, especially of genera Cirsium, Carduus, Cynara, or Onopordum, having prickly leaves and showy flower heads with prickly bracts.
Definitions from Wiktionary.