I would try to locate a book called @your Garden in Spain. It has a lot of minor errors in it but it gives info on all the plants, bushes, trees, bulbs etc. which survive in the Spanish climate. It also details which are frost hardy, drought resistant and various other usful info.

I would look in Spanish gardens, fincas, etc to see what the locals grow. Some that I know do well here apart from those listed above by other members are:
Buddlia,
Canna,
Madonna Lily,
English Blue Bells,
Carpobrotus,
Lantana,
Miribiilis,
yucca,
Aloe vera,
narcissi,
Grape hyacinth (muscari)
Foxtail lily
Freesia,
Gladioli,
Dahlia,
anenome
Cyclamen
roses,
jerusalem artichokes (sunflower type blooms,
Sunflower,
prickly pear,
Dandelion (my neighbour thinks I'm mad but I like them!)
poppies
clover
walnut
hazelnut
pomegranite,
figs
cherry
apple
pear


Hope this helps,
John