''Tetragonia tetragonioides'', commonly called New Zealand spinach, Warrigal greens and other local names, is a flowering plant in the fig-marigold family (

Aizoaceae The Aizoaceae, or fig-marigold family, is a large family of dicotyledonous flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is d ...

). It is often cultivated as a leafy vegetable. It is a widespread species, native to eastern Asia, Australia, and New Zealand. It has been introduced and is an

invasive species An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species ad ...

in many parts of Africa, Europe, North America, and South America. Its natural habitat is sandy shorelines and bluffs, often in disturbed areas. It is a halophyte and grows well in saline ground.

Description

The plant has a trailing habit, and will form a thick carpet on the ground or climb through other vegetation and hang downwards. It can have erect growth when young. The leaves of the plant are 3–15 cm long, triangular in shape, and bright green. The leaves are thick, and covered with tiny

papillae Papilla (Latin, 'nipple') or papillae may refer to: In animals * Papilla (fish anatomy), in the mouth of fish * Basilar papilla, a sensory organ of lizards, amphibians and fish * Dental papilla, in a developing tooth * Dermal papillae, part of ...

that look like waterdrops on the top and bottom of the leaves. The

flower A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechani ...

s of the plant are yellow, and the

fruit In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering. Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in particu ...

is a small, hard capsule covered with small horns.

Taxonomy

Prussian naturalist

Peter Pallas Peter Simon Pallas Fellow of the Royal Society, FRS FRSE (22 September 1741 – 8 September 1811) was a Prussian zoologist and botanist who worked in Russia between 1767 and 1810. Life and work Peter Simon Pallas was born in Berlin, the son ...

described the species as ''Demidovia tetragonoides'' in 1781. German botanist

Otto Kuntze Carl Ernst Otto Kuntze (23 June 1843 – 27 January 1907) was a German botanist. Biography Otto Kuntze was born in Leipzig. An apothecary in his early career, he published an essay entitled ''Pocket Fauna of Leipzig''. Between 1863 and 1866 he ...

placed the species in the genus ''Tetragonia'' in his 1891 work '' Revisio Generum Plantarum'', resulting in its current binomial name. This widely distributed plant has many common names, depending on its location. In addition to the name New Zealand spinach, it is also known as

Botany Bay Botany Bay (Dharawal: ''Kamay''), an open oceanic embayment, is located in Sydney, New South Wales, Australia, south of the Sydney central business district. Its source is the confluence of the Georges River at Taren Point and the Cook ...

spinach, Cook's cabbage, ''kōkihi'' (in

Māori Māori or Maori can refer to: Relating to the Māori people * Māori people of New Zealand, or members of that group * Māori language, the language of the Māori people of New Zealand * Māori culture * Cook Islanders, the Māori people of the C ...

), sea spinach, and tetragon. Its Australian names of Warrigal Greens and Warrigal Cabbage come from the local use of '' warrigal'' to describe plants that are wild (not farmed originally).

Cultivation

It is grown for the

edible leaves This is a list of vegetables which are grown or harvested primarily for the consumption of their leafy parts, either raw or cooked. Many vegetables with leaves that are consumed in small quantities as a spice such as oregano, for medicinal purpo ...

, and can be used as food or an

ornamental plant Ornamental plants or garden plants are plants that are primarily grown for their beauty but also for qualities such as scent or how they shape physical space. Many flowering plants and garden varieties tend to be specially bred cultivars that i ...

for ground cover. It can be an annual or perennial. As some of its names signify, it has similar flavour and texture properties to

spinach Spinach (''Spinacia oleracea'') is a leafy green flowering plant native to central and western Asia. It is of the order Caryophyllales, family Amaranthaceae, subfamily Chenopodioideae. Its leaves are a common edible vegetable consumed either f ...

, and is cooked like spinach. Like spinach, it contains oxalates; its medium to low levels of oxalates need to be removed by

blanching Blanch or blanching may refer to: People * Andrea Blanch (born 1935), portrait, commercial, and fine art photographer * Arnold Blanch (1896–1968), born and raised in Mantorville, Minnesota * Stuart Blanch, Baron Blanch (1918–1994), Anglican bi ...

the leaves in hot water for one minute, then rinsing in cold water before cooking. It thrives in hot weather, and is considered an heirloom vegetable. Few insects consume it, and even

slug Slug, or land slug, is a common name for any apparently shell-less terrestrial gastropod mollusc. The word ''slug'' is also often used as part of the common name of any gastropod mollusc that has no shell, a very reduced shell, or only a smal ...

s and

snail A snail is, in loose terms, a shelled gastropod. The name is most often applied to land snails, terrestrial pulmonate gastropod molluscs. However, the common name ''snail'' is also used for most of the members of the molluscan class Gastro ...

s do not seem to feed on it. The thick, irregularly-shaped

seed A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...

s should be planted just after the last spring

frost Frost is a thin layer of ice on a solid surface, which forms from water vapor in an above-freezing atmosphere coming in contact with a solid surface whose temperature is below freezing, and resulting in a phase change from water vapor (a gas) ...

. Before planting, the seeds should be soaked for 12 hours in cold water, or 3 hours in warm water. Seeds should be planted deep, and spaced apart. The seedlings will emerge in 10–20 days, and it will continue to produce greens through the summer. Mature plant will self-seed. Seeds will overwinter up to USDA zone 5.

As food

The species, rarely used by indigenous people as a leaf vegetable, was first mentioned by Captain Cook. It was immediately picked, cooked, and pickled to help fight

scurvy Scurvy is a disease resulting from a lack of vitamin C (ascorbic acid). Early symptoms of deficiency include weakness, feeling tired and sore arms and legs. Without treatment, decreased red blood cells, gum disease, changes to hair, and bleeding ...

, and taken with the crew of the ''Endeavour''. It spread when the explorer and botanist

Joseph Banks Sir Joseph Banks, 1st Baronet, (19 June 1820) was an English naturalist, botanist, and patron of the natural sciences. Banks made his name on the 1766 natural-history expedition to Newfoundland and Labrador. He took part in Captain James ...

took seeds back to

Kew Gardens Kew Gardens is a botanical garden, botanic garden in southwest London that houses the "largest and most diverse botany, botanical and mycology, mycological collections in the world". Founded in 1840, from the exotic garden at Kew Park, its li ...

during the latter half of the 18th century. For two centuries, ''T. tetragonioides'' was the only cultivated vegetable to have originated from Australia and New Zealand. There are some indications that Māori did eat ''kōkihi'' perhaps more regularly. According to Murdoch Riley, "to counteract the bitterness of the older leaves of this herb, the Māori boiled it with the roots of the convolvulus (''pōhue'')", in reference to species of Convolvulaceae now classified as ''

Calystegia ''Calystegia'' (bindweed, false bindweed, or morning glory) is a genus of about 25 species of flowering plants in the bindweed family Convolvulaceae. The genus has a cosmopolitan distribution in temperate and subtropical regions, but with half o ...

''. The tips of the spinach can be pinched off and eaten raw or cooked.

Nutrition

When consumed after

boiling Boiling is the rapid vaporization of a liquid, which occurs when a liquid is heated to its boiling point, the temperature at which the vapour pressure of the liquid is equal to the pressure exerted on the liquid by the surrounding atmosphere. Th ...

, New Zealand spinach is 95% water, 2%

carbohydrate In organic chemistry, a carbohydrate () is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1 (as in water) and thus with the empirical formula (where ''m'' may or ma ...

s, 1%

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...

, and contains negligible

fat In nutrition science, nutrition, biology, and chemistry, fat usually means any ester of fatty acids, or a mixture of such chemical compound, compounds, most commonly those that occur in living beings or in food. The term often refers spec ...

, while supplying only 12

calorie The calorie is a unit of energy. For historical reasons, two main definitions of "calorie" are in wide use. The large calorie, food calorie, or kilogram calorie was originally defined as the amount of heat needed to raise the temperature of on ...

s (table). In a 100 gram reference amount, the spinach is particularly rich in

vitamin K Vitamin K refers to structurally similar, fat-soluble vitamers found in foods and marketed as dietary supplements. The human body requires vitamin K for post-synthesis modification of certain proteins that are required for blood coagulation ...

, providing 278% of the Daily Value (DV). It also contains appreciable amounts of

vitamin B6 Vitamin B6 is one of the B vitamins, and thus an essential nutrient. The term refers to a group of six chemically similar compounds, i.e., "vitamers", which can be interconverted in biological systems. Its active form, pyridoxal 5′-phosphat ...

vitamin C Vitamin C (also known as ascorbic acid and ascorbate) is a water-soluble vitamin found in citrus and other fruits and vegetables, also sold as a dietary supplement and as a topical 'serum' ingredient to treat melasma (dark pigment spots) an ...

, and

manganese Manganese is a chemical element with the symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese is a transition metal with a multifaceted array of industrial alloy use ...

(18-25% DV).

Gallery

File:Tetragonia flower MRD Otari.jpg, Flower File:Tetragonia tetragonioides (Flower).jpg, ''T. tetragonioides'' showing erect growth

References

External links

* {{Authority control tetragonioides Bushfood Caryophyllales of Australia Crops originating from Argentina Crops originating from Asia Crops originating from Australia Crops originating from Chile Crops originating from New Zealand Eudicots of Western Australia Flora of Japan Flora of New South Wales Flora of Norfolk Island Flora of Lord Howe Island Flora of South Australia Flora of Queensland Flora of Tasmania Flora of Victoria (Australia) Leaf vegetables