The Spanish bluebell has undergone frequent re-christening by the botanists, and is better known as Endymion hispanicus. I presume that they previously called it Endymion after the beautiful son of Zeus who had the gift of eternal youth. There are many legends about Endymion, most of them disreputable, and Keats wrote an excessively long poem about him of which I will forbear to remind you of the first line, for you know it too well.
However that may be, Hyacinthoides is a tall scilla, a Mediterranean species which is much like the English bluebell, but larger in flower and, and without the characteristic droop of our woodland flower, which is lovely in the wild but insignificant in the garden. It in late spring and is a perfect bulb for naturalizing among small trees or shrubs. The bells are either blue, pink or white, and look charming in a mixture, perhaps under azaleas, though one of the nicest plantings I know is in a small town garden, where the blue only are grown under the early-flowering yellow rose, ‘Canary Bird’. I have also seen the bulbs naturalized in an apple orchard, and I sometimes think we grow apples as a shelter for bulbs or a prop for climbing roses rather than for the fruit.
The bulbs like a soil with a little moisture, and preferably some lime, but will grow in drier soil if there is shade. Plant them 3 inches (7.5 cm) deep in random.