Spring greens are a cultivar

Cultivar

A cultivar'Cultivar has two meanings as explained under Formal definition. When used in reference to a taxon, the word does not apply to an individual plant but to all those plants sharing the unique characteristics that define the cultivar. is a plant or group of plants selected for desirable...

 of Brassica oleracea

Brassica oleracea

Brassica oleracea, or wild cabbage, is a species of Brassica native to coastal southern and western Europe, where its tolerance of salt and lime and its intolerance of competition from other plants typically restrict its natural occurrence to limestone sea cliffs, like the chalk cliffs on both...

in the cultivar Acephala Group

Acephala Group

The Acephala Group is a cultivar group for the species Brassica oleracea. It includes the following:* kale* collard greens* spring greens...

, similar to kale

Kale

Kale is very high in beta carotene, vitamin K, vitamin C, lutein, zeaxanthin, and reasonably rich in calcium. Kale, as with broccoli and other brassicas, contains sulforaphane , a chemical with potent anti-cancer properties. Boiling decreases the level of sulforaphane; however, steaming,...

, in which the central leaves do not form a head or form only a very loose one. It is considered to be closer to wild cabbage

Brassica oleracea

Brassica oleracea, or wild cabbage, is a species of Brassica native to coastal southern and western Europe, where its tolerance of salt and lime and its intolerance of competition from other plants typically restrict its natural occurrence to limestone sea cliffs, like the chalk cliffs on both...

 than most other domesticated forms, and is grown primarily in northern Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

, where its tolerance of cold winter

Winter

Winter is the coldest season of the year in temperate climates, between autumn and spring. At the winter solstice, the days are shortest and the nights are longest, with days lengthening as the season progresses after the solstice.-Meteorology:...

s is valued for an early spring

Spring (season)

Spring is one of the four temperate seasons, the transition period between winter and summer. Spring and "springtime" refer to the season, and broadly to ideas of rebirth, renewal and regrowth. The specific definition of the exact timing of "spring" varies according to local climate, cultures and...

 supply of edible leaves. The Cultivar Group

Cultivar group

In naming cultivated plants, a Group is a formal classification category, under the International Code of Nomenclature for Cultivated Plants :The term "Group" was introduced in the 2004 ICNCP, replacing the "Cultivar-group" of the 1995 ICNCP.A Group is united by some common trait; for example...

 Acephala also includes curly kale

Kale

Kale is very high in beta carotene, vitamin K, vitamin C, lutein, zeaxanthin, and reasonably rich in calcium. Kale, as with broccoli and other brassicas, contains sulforaphane , a chemical with potent anti-cancer properties. Boiling decreases the level of sulforaphane; however, steaming,...

 and collard greens

Collard greens

Collard greens are various loose-leafed cultivars of Brassica oleracea , the same species as cabbage and broccoli. The plant is grown for its large, dark-colored, edible leaves and as a garden ornamental, mainly in Brazil, Portugal, the southern United States, many parts of Africa, Montenegro,...

, which are extremely similar genetically.

The term is also used more loosely to refer to thinnings and trimmed-off leaves of other types of Brassica

Brassica

Brassica is a genus of plants in the mustard family . The members of the genus may be collectively known either as cabbages, or as mustards...

, including turnip and swede

Rutabaga

The rutabaga, swede , turnip or yellow turnip is a root vegetable that originated as a cross between the cabbage and the turnip; see Triangle of U...

 leaves, surplus thinned out young cabbage

Cabbage

Cabbage is a popular cultivar of the species Brassica oleracea Linne of the Family Brassicaceae and is a leafy green vegetable...

 plants and leaves from cauliflower

Cauliflower

Cauliflower is one of several vegetables in the species Brassica oleracea, in the family Brassicaceae. It is an annual plant that reproduces by seed...

 and brussels sprouts.

In all cases, the leaves, being loose, are fully exposed to light, and so are dark green, coarse, often tough, and more strongly flavoured than many people prefer, but are also particularly rich in vitamin

Vitamin

A vitamin is an organic compound required as a nutrient in tiny amounts by an organism. In other words, an organic chemical compound is called a vitamin when it cannot be synthesized in sufficient quantities by an organism, and must be obtained from the diet. Thus, the term is conditional both on...

 C

Vitamin C

Vitamin C or L-ascorbic acid or L-ascorbate is an essential nutrient for humans and certain other animal species. In living organisms ascorbate acts as an antioxidant by protecting the body against oxidative stress...

, folic acid

Folic acid

Folic acid and folate , as well as pteroyl-L-glutamic acid, pteroyl-L-glutamate, and pteroylmonoglutamic acid are forms of the water-soluble vitamin B9...

 and dietary fibre, making them a very healthy food.