I think that these bluebells that have swamped the borders of my garden are English bluebells (update – but see below) rather than the evil Spanish bluebells that Germaine Greer takes exception to. I think they're the English variety because they have fairly purple stems and are bowed over under the weight of the flowers, rather than stiff and upright like their more vigorous Spanish cousins.
Apparently the Spanish variety hybridises with the English but the Spanish characteristics win out in the hybrid and ultimately the English one is out-competed and disappears. Hence some parties are very worried about the fate of the English bluebell, especially since well meaning people that are none the wiser plant Spanish bluebells in their gardens and even nature reserves. Germaine complains about bulb companies selling Spanish under the name of English, compounding the confusion and the problem.
Coming back to my picture above (taken on an iPhone – so please excuse the murky quality) I'm not completely sure whether they're really true English, as they bear some characteristics of each judging by the descriptions and photos in the two Wikipedia articles linked above. Maybe these are hybrids and the battle is already lost in my garden?
Update: my learned friends who know about this sort of thing inform me that these are not English, and are at best hybrids. Oh well.