In botany terms the difference between flower and kousso

is that flower is 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 kousso is an Ethiopian rosaceous tree whose flowers were used as a vermifuge, species: Hagenia abyssinica.

As nouns the difference between flower and kousso

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 while kousso is an Ethiopian rosaceous tree whose flowers were used as a vermifuge, species: Hagenia abyssinica.

As a verb flower

is to put forth blooms.