Donkey’s over being attached to sticky part of plant (5)

I believe the answer is:
burro
'donkey's' is the definition.
(term for a small donkey)
'over being attached to sticky part of plant' is the wordplay.
'over' becomes 'o' (cricket abbreviation).
'being attached to' is a charade indicator (letters next to each other).
'sticky part of plant' becomes 'burr' (I can't explain this - if you can you should give a lot more credence to this answer).
'o' after 'burr' is 'BURRO'.
Can you help me to learn more?
(Other definitions for burro that I've seen before include "Spanish donkey" , "Beast of burden" , "Small donkey used as a pack animal" , "Small donkey (US)" .)
