Something inserted in a pot I ordered it's a shrub (10)
I believe the answer is:
'a shrub' is the definition.
(poinsettia is a kind of shrub)
'something inserted in a pot i ordered' is the subsidiary indication.
'something inserted' becomes 'inset' (I've seen this before).
'in' indicates putting letters inside.
'ordered' is an anagram indicator.
'apoti' with letters rearranged gives 'potia'.
'inset' placed inside 'potia' is 'poinsettia'.
'it's' is the link.
(Other definitions for poinsettia that I've seen before include "bloom" , "Plant with showy bracts, usu. red, pink or white" , "Shrub often given at Christmas" , "American plant" , "poisonous bush" .)