Petitions a foreign plant (10)
I believe the answer is:
poinsettia
'plant' is the definition.
The answer is an example.
'petitions a foreign' is the wordplay.
'foreign' is an anagram indicator (foreign order of the letters).
'petitions'+'a'='petitionsa'
'petitionsa' with letters rearranged gives 'POINSETTIA'.
(Other definitions for poinsettia that I've seen before include "Ornamental house plant" , "poisonous bush" , "Shrub often given at Christmas" , "Plant with showy bracts, usu. red, pink or white" , "Flower popular at Christmas" .)