Originally from http://flowerthere.com/tulips-images/
The tulip was introduced inside the Netherlands in 17th century when Holland had been a wealthy country. Rich merchants had enough money and started trading bulbs on stock market trading, similare to futures. Bulbs were overpriced (such as the internet bubble) and investors begun to cash their profits.
Some buyers failed to purchase their people and purchase were afraid which they would be tied to their trading and bulbs ceased. Many individuals lost huge quantities of money.
More at Tulips as a currency