Records of non-U plants (6)

I believe the answer is:

annals

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'records' is the definition.
(I've seen this in another clue)

I cannot understand how the rest of the clue works.

(Other definitions for annals that I've seen before include "Yearly records" , "Record of events year by year" , "Registers" , "The Four Masters wrote them in 17th century" , "History of events year by year" .)

I've seen this clue in The Globe and Mail, The Telegraph and The Guardian.

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