Leaf vegetables, also called leafy greens, pot herbs, vegetable greens, or simply greens, are plant leaves eaten as a vegetable, sometimes accompanied by tender petioles and shoots. Leaf vegetables eaten raw in a salad can be called salad greens.
Nearly one thousand species of plants with edible leaves are known. Leaf vegetables most often come from short-lived herbaceous plants, such as lettuce and spinach. Woody plants of various species also provide edible leaves.
The leaves of many fodder crops are also edible for humans, but are usually only eaten under famine conditions. Examples include alfalfa, clover, and most grasses, including wheat and barley. Food processing, such as drying and grinding into powder or pulping and pressing for juice, may be used to involve these crop leaves in a diet.
Leaf vegetables contain many typical plant nutrients, but since they are photosynthetic tissues, their vitamin K levels are particularly notable. Phylloquinone, the most common form of the vitamin, is directly involved in photosynthesis.
The vitamin K content of leaf vegetables is particularly high, since these are photosynthetic tissues and phylloquinone is involved in photosynthesis.[2] Accordingly, users of vitamin K antagonist medications, such as warfarin, must take special care to limit the consumption of leaf vegetables.[3]
Large pot of collard greens being prepared on a US Navy ship
If leaves are cooked for food, they may be referred to in the United Statesasboiled greens. Leaf vegetables may be stir-fried, stewed, steamed, or consumed raw. Leaf vegetables stewed with pork is a traditional dish in soul food and Southern U.S. cuisine. They are also commonly eaten in a variety of South Asian dishes such as saag. Leafy greens can be used to wrap other ingredients into an edible package in a manner similar to a tortilla. Many green leafy vegetables, such as lettuce or spinach, can also be eaten raw, for example in sandwichesorsalads. A green smoothie enables large quantities of raw leafy greens to be consumed by blending the leaves with fruit and water.
Ligurian pansoti filled with preboggion boiled greens and served with nut sauce
Preboggion, a mixture of different wild boiled leaf vegetables, is used in Ligurian cuisine to stuff ravioli and pansoti.[7] One of the main ingredients of preboggion are borage(Borago officinalis) leaves.
Preboggion is also sometimes added to minestrone soup and frittata.[8]
Botwinka (or boćwinka) is a soup that features beet stems and leaves as one of its main ingredients. The word "botwinka" is the diminutive form of "botwina" which refers to leafy vegetables like chard and beet leaves.
Postharvest diseases cause up to 50% losses of leaf vegetables. These are fungal, bacterial, and much less commonly viral. The most important remedy is temperature controlled storage, although also important is prevention of mechanical damage to produce as this provides entryways for pathogens. Uncontaminated water for washing of the vegetables is of lesser but still significant importance.[10]
^National Research Council (U.S.), Board on Science and Technology for International Development, Lost Crops of Africa: Vegetables, pp. 6, 35f. BooksArchived 20 March 2015 at the Wayback Machine
^"ECHO". Archived from the original on 10 May 2010. Retrieved 6 May 2019.
^Thayer, Samuel (2017). Incredible Wild Edibles. Forager's Harvest. pp. 273, 276. ISBN978-0-9766266-2-6. Pokeweed must be prepared properly or it is dangerous. ... The only parts of poke to be eaten are the young shoots and tender stem tips, along with their immature, meristematic leaves. These must be boiled in an ample pot of water and then drained. Eating poke raw can cause serious poisoning. ... [A] man became ill from drinking water in which mature poke leaves had been boiled (Jaeckle and Freemon 1981).