The "Madonna dei Fiori" of Bra, repeatedly flowering out of season as it has done for 650 years, is a genuine scientific puzzle. The bushes that still grow vigorously behind their railings, are prunus spinosa, to use the Latin name, but are commonly known as "blackthorn." They belong to the rose family and usually flower once a year, in March if the season is mild or in April if it is harsh. Since the 17th century, Italian scientists (among whom, on occasions, are those from the College of Agriculture at the University of Turin) have carried out detailed studies establishing that these incredible blackthorns are in every respect identical to those that grow just about anywhere and they are identical to the numerous examples that grow around Bra. The soil is also similar. There are no geophysical reasons, underground currents, either of electricity or water that can explain this extraordinary winter flowering. Furthermore, the bushes face north and therefore only benefit from feeble light and heat from the sun, and are not favored by any particular micro-climate.