Sticky stuff covering poor Arnie’s flower (8)
I believe the answer is:
geranium
'flower' is the definition.
(I've seen this before)
'sticky stuff covering poor arnie's' is the wordplay.
'sticky stuff' becomes 'gum'.
'covering' is an insertion indicator.
'poor' indicates an anagram.
'arnie' anagrammed gives 'erani'.
'gum' enclosing 'erani' is 'GERANIUM'.
(Other definitions for geranium that I've seen before include "Commonly cultivated plant" , "Cultivated pelargonium" , "Cultivated cranesbill" , "Showy garden flower, often seen in window-boxes" , "Run image of the flower" .)