Leaf vegetables, also called leafy greens, vegetable greens, or simply greens, are plant leaf eaten as a vegetable, sometimes accompanied by their petioles and shoots, if tender. Leaf vegetables eaten raw in a salad can be called salad greens, whereas leaf vegetables eaten cooked can be called pot herbs.
Nearly one thousand species of plants with edible leaves are known. Leaf vegetables most often come from short-lived , 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 Poaceae, including wheat and barley. Food processing, such as drying and grinding into powder or pulping and pressing for juice, may involve these crop leaves in a diet.
Leaf vegetables contain many typical plant nutrients, but their vitamin K levels are particularly notable since they are photosynthetic tissues. Phylloquinone, the most common form of the vitamin, is directly involved in photosynthesis.
Nutrition
Spinach, as an example of a leaf vegetable, is low in
calories and
fat per calorie, and high in
dietary fiber,
vitamin C, pro-
vitamin A carotenoids,
folate,
manganese and
vitamin K.
The vitamin K content of leaf vegetables is particularly high since these are photosynthetic tissues, and phylloquinone is involved in photosynthesis.
Preparation
If leaves are cooked for food, they may be referred to in the
United States as
boiled greens. Leaf vegetables may be
stir frying,
,
steaming, 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 South Asian dishes such as
saag. Leafy greens can be used to wrap other ingredients into an edible package like a
tortilla. Many green leafy vegetables, such as lettuce or spinach, can also be eaten raw, for example, in
or
. A
green smoothie enables large quantities of raw leafy greens to be consumed by blending the leaves with fruit and water.
Africa
In certain countries of Africa, various species of nutritious
amaranth are widely eaten boiled.
[National Research Council (U.S.), Board on Science and Technology for International Development, Lost Crops of Africa: Vegetables, pp. 6, 35f. Books ]
Celosia argentea var. argentea or "Lagos spinach" is one of the main boiled greens in West African cuisine.
Greece
In
Greek cuisine,
khorta (χόρτα, literally 'greens') are a typical side dish, eaten hot or cold and usually seasoned with
olive oil and
lemon.
At least 80 different kinds of greens are used, depending on the area and season, including black mustard, dandelion, wild sorrel, chicory, fennel, chard, kale, mallow, Solanum nigrum, lamb's quarters, wild leeks, hoary mustard, charlock, smooth sow thistle and even the fresh leaves of the caper plant.
Italy
Preboggion, a mixture of different wild boiled leaf vegetables, is used in
Ligurian cuisine to stuff
ravioli and
pansoti.
One of the main ingredients of
preboggion are
borage (Borago officinalis) leaves.
Preboggion is also sometimes added to
minestrone soup and
frittata.
Poland
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.
United States
In the cuisine of the Southern United States and
Soul food,
turnip,
collard greens,
kale,
garden cress,
dandelion,
mustard plant, and
pokeweed greens are commonly cooked and often served with pieces of
ham or
bacon. The boiling water, called
potlikker, is used as
broth. Water in which pokeweed has been prepared contains toxins that have been removed by boiling and should be discarded.
Sauteed escarole is a primary ingredient in the Italian-American dish Utica greens.
List of leaf vegetables
-
Agastache foeniculum — anise hyssop (western North America)
-
Allium fistulosum — Welsh onion (East Asia)
-
Alternanthera sissoo — sissoo spinach (Brazil)
-
Basella alba — Malabar spinach (India, Southeast Asia, New Guinea)
-
Beta vulgaris — beets, including beet greens, Swiss chard
-
Brassica oleracea — wild cabbage, including cabbage, gai lan, Jersey cabbage, kale, red cabbage, savoy cabbage, collard greens, mustard greens, kohlrabi and more
-
Brassica rapa — field mustard, including napa cabbage, bok choy, bomdong, choy sum, komatsuna, rapini, tatsoi, radish greens, and more
-
Campanula versicolor — various-colored bellflower (southeastern Italy to the Balkans)
-
Chenopodium quinoa — quinoa (western Andes of South America)
-
Cichorium endivia — endive, including escarole
-
Chicory — chicory (Europe)
-
Claytonia perfoliata — palsingat (western North America)
-
Cnidoscolus aconitifolius — chaya (Yucatán Peninsula of Mexico)
-
Carrot — carrot (Europe and Southwestern Asia)
-
Eruca sativa — arugula or rocket (Mediterranean region)
-
Foeniculum vulgare — fennel (southern Europe)
-
Gynura bicolor — edible gynura (China, Thailand, Myanmar)
-
Gynura procumbens — longevity spinach (China, Southeast Asia, and Africa)
-
Hemerocallis fulva — orange day-lily (China or Japan)
-
Lepidium meyenii — maca (Andes)
-
Lettuce — lettuce, including celtuce, iceberg lettuce, red leaf lettuce, romaine lettuce
-
Nasturtium officinale — watercress (Europe and Asia)
-
Malva moschata — musk mallow (Europe and southwestern Asia)
-
Moringa oleifera — moringa (Indian subcontinent)
-
Perilla frutescens — shisho perilla (Southeast Asia and Indian highlands)
-
Rumex acetosa — garden sorrel (most of Europe, temperate Asia, North America, and Greenland)
-
Sassafras albidum — sassafras (eastern North America)
-
Sauropus androgynus — katuk (South Asia and Southeast Asia)
-
Spinacia oleracea — spinach (central and western Asia)
-
Solanum aethiopicum — nakati (Asia and tropical Africa)
-
Fenugreek — fenugreek (India)
-
Tropaeolum majus — garden nasturtium (Andes)
-
Viola odorata — sweet violet (Europe, northern Africa, Syria)
Postharvest diseases
Postharvest diseases cause up to 50% losses of leaf vegetables. These are fungal, bacterial, and much less commonly
plant virus. The most important remedy is temperature-controlled storage, although it is also important to prevent mechanical damage as this provides entryways for pathogens. Uncontaminated water for washing vegetables is of lesser but still significant importance.
[ ]
Common bacterial pathogens include: Xanthomonas campestris pv. vitians, Pseudomonas viridiflava, P. cichorii, and P. marginalis, P. syringae pv. aptata, X. campestris pv. campestris, X. campestris pv. raphani, P. syringae pv. maculicola, P. syringae pv. alisalensis, Pectobacterium spp. including Pectobacterium carotovorum subsp. odoriferum and Pectobacterium aroidearum, Dickeya spp., Pseudomonas marginalis, and Pseudomonas viridiflava.
Common fungal pathogens include: Alternaria brassicicola, A. alternata, A. arborescens, A. tenuissima, A. japonica, Colletotrichum higginsianum, Colletotrichum dematium f. spinaciae, Microdochium panattonianum, Stemphylium botryosum, Cladosporium variabile, Cercospora beticola, C. lactucae-sativae, C. brassicicola, C. acetosella, Botrytis cinerea, Golovinomyces cichoracearum, Podosphaera fusca, Erysiphe cruciferarum, E. polygoni, E. heraclei, Sclerotinia sclerotiorum, and S. minor.
Common oomycete pathogens include: Albugo occidentalis, A. ipomoeae-aquaticae, Albugo candida, Hyaloperonospora parasitica, Bremia lactucae, Peronospora effusa, and Peronospora farinosa f.sp. betae.
such as prochloraz can be used to manage some of these.
== Gallery ==
