@sandraescapes I'm afraid I don't know. They were given to me by my Portuguese allotment neighbour whom I think got them from Spain. Anyway, they're much bigger than the ones I planted from the local garden centre. Will keep one bulb for replanting in the autumn.
@juneees make sure you plant them in the autumn for good sized bulbs. Generally the reason it will flower is lack of water. Keep them watered during the Spring. To be fair I am lazy and plant them October/November and then just leave them to do their own thing.