Most of the global population relies on crops from just 30 plant species in their diet. However, many more species are important food sources – around 7,000 plant species have been used by humans for food – and fungi also play a vital role in food production.
Food
Humans rely on plants to provide them with the vast majority of their food. Staple crops such as rice, wheat, cassava, potatoes, and chickpeas all come from plants. Without plants, luxuries such as chocolate, honey, sugar, nuts, herbs, and spices would not be available to us.
Plants can supply all the essential parts of a healthy human diet. Carbohydrates such as starch (a valuable energy source) are found in seeds, grains, and tubers (for example oats, rice, and potatoes). Pulses, from the pea and bean family (Leguminosae) provide us with proteins.
The rich variety of vegetable oils that can be obtained from plants (such as olive oil from Olea europea) contribute to the fats needed in a healthy diet. Fruits and vegetables are valuable sources of vitamins and minerals.
Drink
Coffee and tea, and even the sugar you add to sweeten them, are sourced from plants. About 1.5 billion cups of coffee and over 3 billion cups of tea are consumed worldwide every day, so the plants from which these drinks are produced are important to many people’s lives.
All alcoholic drinks are made using plant material. Beer, perhaps the world’s oldest alcoholic drink, is produced using malted cereal grains. Hops (Humulus lupulus) can also be added to provide flavour and the characteristic bitter taste. Many alcoholic drinks are fruit-based, such as wine, which is made using grapes, and cider, from apples.
Other drinks, including fruit juices, cordials, hot drinking chocolate, colas, and coconut milk, also owe their existence to plants.
Herbs and spices
The spicy red fruit growing on this chili pepper plant at Kew Gardens The herbs and spices used to add flavor to our food are obtained from a wide range of plant parts, including roots, fruits, leaves, and seeds. The aromas of herbs and spices are the result of volatile chemicals that are released, for example, when they are crushed or chewed, or on ripening. Popular herbs and spices include ginger, lemongrass, chili pepper, rosemary, oregano, and allspice.
Capsicum fruits, including the chili pepper, have been part of the human diet for at least 10,000 years.
Fungi
Fungi, especially the yeast Saccharomyces cerevisiae, provide us with numerous foods and beverages, including staples like bread and beer. Button mushroom (Agaricus bisporus) is one of the most commonly cultivated and widely consumed mushrooms in the world, but there are many more edible species.