Brassica rapa rapa
These are very popular vegetable in Italy, especially in the South. There are an enormous number of varieties. The most common are Novantina and Centoventina (90 and 120 days) for the number of days it takes for the particular variety to mature. Cima di rapa is easy to grow if you follow a few simple rules. First, you can grow it at any time of the year. You do NOT have to grow it in cool weather. For example they do better in the summer in the Northeast U.S. because flea beetles are a real problem for cima di rapa in the spring. In southern Italy, they are planted in late summer and are harvested through the mild winter (that is the reason to grow varieties with different days to maturity: plant them all at the same time then harvest for months). Grow it that way if you live in an area with Mediterranean climate or with mild winters. In zones 6 through 4, they do very well if planted in summer or late summer.