Regarding plants in food there are six general groups, the herbs, the spices, the fruits, the vegetables, the staples and the nuts.
This fun fact is written in culinary terms. There are various ways culinary and botanical definitions of these terms vary, namely involving the Great Tomato Debate. The following definitions are used in culinary practice, not botany.
Spices, such as mustard, ginger, pepper and cinnamon, are the seeds, roots, fruits or barks of plants used to add extra flavor to a food substance, but not generally eaten on their own (see: the cinnamon challenge).
Herbs, such as basil, mint or rosemary, are the leafy parts of plants used, like spices, to add extra flavor to a food substance, but not generally eaten on their own.
Fruits, vegetables and staples are all generally eaten as a food product, rather than used to add flavor. A fruit is the sweet part of a plant generally containing the seed of the plant.
Nuts are any hard, oily seed contained within a shell, including peanuts, walnuts, cashews, hazelnuts and chestnuts.
Vegetables, such as broccoli, onions and eggplant, are the parts of a plant, usually the leafy parts, roots and buds, that have a savory flavor.
Finally, staples are plant seeds, roots, and fruits (in the botanical sense) that comprise a large part of a culture’s diet and have a high caloric value and provide carbohydrates, proteins and/or fats. As of 2010 the three most used staple foods are corn, wheat and rice.