Good article …
There are two species of bluebell found in the UK. Native or British bluebell and non-native Spanish bluebell. Cross-breeding between the two species means you may spot flowers which combine traits from both.
The easiest way to tell the difference between native and non-native bluebells is to look at the colour of the pollen. If it is creamy-white then the bluebell is native. If it is any other colour such as pale green or blue then it’s not native.