The female has a miniature courgette fruit at its base of the flower whereas the male doesn’t.
The flowers have been cut to expose the male pollen and female stigma.
In rainy weather, the courgettes can fail to form due to a lack of insects needed to pollinate the female flower.
You can dab the pollen from the male flower on to the stigma of the female flower. The flowers have been cut open to expose the male pollen and the female stigma. The female flower will need to be open to be pollinated. This photograph is of an immature female flower which has not opened yet.
Photography Neil Bromhall www.complete-gardens.co.uk