Blue-flowered graphite (8)

I believe the answer is:

plumbago

I'm a little stuck... Click here to teach me more about this clue!

'graphite' is the definition.
(I know that graphite can be written as plumbago)

I cannot understand how the rest of the clue works.

Can you help me to learn more?

(Other definitions for plumbago that I've seen before include "lead" , "Shrub; graphite" , "climber in bed" , "Blue-flowered plant" , "Word for graphite" .)

I've seen this clue in the Sydney Morning Herald.

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