Botanical book? (6)
I believe the answer is:
annual
This clue could be a double definition.
'botanical' is the first definition.
Both the answer and definition are adjectives. Maybe there's an association between them I don't understand?
'book?' is the second definition.
(annual is a kind of book)
Can you help me to learn more?
(Other definitions for annual that I've seen before include "Reference book that's published every year" , "Happening once each year" , "Lasting for a year" , "Twelve-monthly" , "Yearly publication" .)