In botany|lang=en terms the difference between flower and bracteole

is that flower is (botany) a reproductive structure in angiosperms (flowering plants), often conspicuously colourful and typically including sepals, petals, and either or both stamens and/or a pistil while bracteole is (botany) a bract subtending an individual flower rather than an inflorescence.

As nouns the difference between flower and bracteole

is that flower is a colorful, conspicuous structure associated with angiosperms, frequently scented and attracting various insects, and which may or may not be used for sexual reproduction or flower can be something that flows, such as a river while bracteole is (botany) a small leaf of leaf-like structure directly subtending a flower or inflorescence whose stalk itself is subtended by a bract.

As a verb flower

is to put forth blooms.