Widely cultivated tropical climbing plant (13)

I believe the answer is:

bougainvillea

(Other definitions for bougainvillea that I've seen before include "Woody climbing plant with conspicuous flower-heads" , "Ornamental tropical climber" , "Tropical woody climbing plant with red or purple bracts" , "Common climbing plant of the tropics" .)

I've seen this clue in The Times and The Sunday Times.

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