Tree sample provided by stuck-up botanical illustrator (5)
I believe the answer is:
lilac
'tree sample' is the definition.
'lilac' can be an answer for 'tree' (I've seen this before). I am not certain of the 'sample' bit.
'provided by stuck-up botanical illustrator' is the wordplay.
'stuck up' says the letters should be written backwards.
'provided by' says the answer is hidden in the clue (the answer is provided within the clue).
'calil' is hidden within 'botanical illustrator'.
'calil' written backwards gives 'LILAC'.
Can you help me to learn more?
(Other definitions for lilac that I've seen before include "Drop by about one, turning" , "Genus Syringa shrub" , "Shrub with fragment purple or white flowers" , "Lavender colour" , "Syringa vulgaris, light purple in colour" .)