Centaurea is likely misspelled.
Centaurea has no English definition.
As a noun knapweed is
any of various common weeds of the genus
Centaurea
centaurea
Not English
Centaurea has no English definition. It may be misspelled.
knapweed
English
Noun
(
en noun)
Any of various common weeds of the genus Centaurea
# especially .