Belgian endive is the compact, hypertrophied bud of witloof chicory obtained by forcing the plant in dark conditions.  

 

In 19th century Belgium, a man who had forgotten his chicory roots in a cellar was amazed to discover them plump and covered with long yellowish leaves which had sprouted in the dark, warm conditions. Curious, he tasted them, found they had a good flavor, and began to cultivate them. However, it is to another Belgian that we owe endive as it is eaten today: the botanist Brézier who developed it from coffee chicory which had a small root. The market stalls of the capital began to display this new vegetable in 1846, and it quickly became known as Brussels endive.