3,030. Three Types of Edible Plants

Hilchos Kilayim 1:8

There are three types of edible plants: (1) grain, which includes such things as wheat, barley, oats and spelt, among others; (2) "legumes" (kitniyos), which includes all the seeds eaten by people other than grain – beans, peas, lentils, millet, rice, sesame, poppy, etc.; and (3) gardening seeds, which are not themselves suitable for human consumption, but their produce is. These include the seeds of onion, garlic, leeks, cabbage, et al. Flax falls into this category. When these seeds are planted and start to grow, before they become recognizable, the whole plant is called vegetation and they are called vegetables.

Hilchos Kilayim 1:9

Some garden plants, like flax and mustard, are planted in fields and are called “species of seeds.” Other garden plants – like turnips, radishes, spinach, onions, coriander, parsley, horseradish, etc. – people are only accustomed to plant in small rows. We call these “species of vegetables.”