Tetragonia tetragonoides
Encyclopedia
Tetragonia tetragonioides (or previously T.expansa) is a leafy groundcover also known as New Zealand Spinach, Warrigal Greens, Kokihi (Māori language
), Sea Spinach, Botany Bay Spinach, Tetragon and Cook's Cabbage. It is native to New Zealand
, Australia
, Japan
, Chile
and Argentina
.
The species, rarely used by Māori or other indigenous people as a leaf vegetable
, was first mentioned by Captain Cook
. It was immediately picked, cooked, and pickled to help fight scurvy
, and taken with the crew of the Endeavour
. It spread when the explorer and botanist Joseph Banks
took seeds back to Kew Gardens during the latter half of the 18th century. For two centuries T.tetragonioides was the only cultivated vegetable that originated from Australia and New Zealand.
The species prefers a moist environment for growth. The plant grows flat on the ground. 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 that look like waterdrops on the top and bottom of the leaves. The flower
s of the plant are yellow, and the fruit
is a small, hard pod covered with small horns. The plant is a halophyte
and grows well in saline
ground.
for ground cover. As some of its names signify, it has similar flavour and texture properties to spinach
, and is cooked like spinach. Like spinach it contains oxalate
s: T.tetragonioides medium to low levels of oxalates need to be removed by blanching the leaves in hot water for one minute, then rinsing in cold water before cooking. It can be found as an invasive plant in North
and South America
, and has been cultivated along the East Asia
n rim. It thrives in hot weather, and is considered an heirloom vegetable. Few insects will bother it, and even slug
s and snail
s do not seem to bother it.
The thick, irregularly-shaped seed
s should be planted just after the last spring frost
. Before planting, the seeds should be soaked for 12 hours in cold water, or 3 hours in warm water. Seeds should be planted 5–10 mm deep, and spaced 15–30 cm apart. The seedlings will emerge in 10–20 days, and it will continue to produce greens through the summer.
Maori language
Māori or te reo Māori , commonly te reo , is the language of the indigenous population of New Zealand, the Māori. It has the status of an official language in New Zealand...
), Sea Spinach, Botany Bay Spinach, Tetragon and Cook's Cabbage. It is native to New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
, Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
, Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...
and Argentina
Argentina
Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...
.
The species, rarely used by Māori or other indigenous people as a leaf vegetable
Leaf vegetable
Leaf vegetables, also called potherbs, green vegetables, greens, leafy greens or salad greens, are plant leaves eaten as a vegetable, sometimes accompanied by tender petioles and shoots...
, was first mentioned by Captain Cook
James Cook
Captain James Cook, FRS, RN was a British explorer, navigator and cartographer who ultimately rose to the rank of captain in the Royal Navy...
. It was immediately picked, cooked, and pickled to help fight scurvy
Scurvy
Scurvy is a disease resulting from a deficiency of vitamin C, which is required for the synthesis of collagen in humans. The chemical name for vitamin C, ascorbic acid, is derived from the Latin name of scurvy, scorbutus, which also provides the adjective scorbutic...
, and taken with the crew of the Endeavour
HM Bark Endeavour
HMS Endeavour, also known as HM Bark Endeavour, was a British Royal Navy research vessel commanded by Lieutenant James Cook on his first voyage of discovery, to Australia and New Zealand from 1769 to 1771....
. It spread when the explorer and botanist Joseph Banks
Joseph Banks
Sir Joseph Banks, 1st Baronet, GCB, PRS was an English naturalist, botanist and patron of the natural sciences. He took part in Captain James Cook's first great voyage . Banks is credited with the introduction to the Western world of eucalyptus, acacia, mimosa and the genus named after him,...
took seeds back to Kew Gardens during the latter half of the 18th century. For two centuries T.tetragonioides was the only cultivated vegetable that originated from Australia and New Zealand.
The species prefers a moist environment for growth. The plant grows flat on the ground. 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 that look like waterdrops on the top and bottom of the leaves. The flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
s of the plant are yellow, and the fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...
is a small, hard pod covered with small horns. The plant is a halophyte
Halophyte
A halophyte is a plant that grows where it is affected by salinity in the root area or by salt spray, such as in saline semi-deserts, mangrove swamps, marshes and sloughs, and seashores. An example of a halophyte is the salt marsh grass Spartina alterniflora . Relatively few plant species are...
and grows well in saline
Salinity
Salinity is the saltiness or dissolved salt content of a body of water. It is a general term used to describe the levels of different salts such as sodium chloride, magnesium and calcium sulfates, and bicarbonates...
ground.
Cultivation
It is grown for the edible leaves, and can be used as food or an ornamental plantOrnamental plant
Ornamental plants are plants that are grown for decorative purposes in gardens and landscape design projects, as house plants, for cut flowers and specimen display...
for ground cover. As some of its names signify, it has similar flavour and texture properties to spinach
Spinach
Spinach is an edible flowering plant in the family of Amaranthaceae. It is native to central and southwestern Asia. It is an annual plant , which grows to a height of up to 30 cm. Spinach may survive over winter in temperate regions...
, and is cooked like spinach. Like spinach it contains oxalate
Oxalate
Oxalate , is the dianion with formula C2O42− also written 22−. Either name is often used for derivatives, such as disodium oxalate, 2C2O42−, or an ester of oxalic acid Oxalate (IUPAC: ethanedioate), is the dianion with formula C2O42− also written (COO)22−. Either...
s: T.tetragonioides medium to low levels of oxalates need to be removed by blanching the leaves in hot water for one minute, then rinsing in cold water before cooking. It can be found as an invasive plant in North
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
and South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
, and has been cultivated along the East Asia
East Asia
East Asia or Eastern Asia is a subregion of Asia that can be defined in either geographical or cultural terms...
n rim. It thrives in hot weather, and is considered an heirloom vegetable. Few insects will bother it, and even slug
Slug
Slug is a common name that is normally applied to any gastropod mollusc that lacks a shell, has a very reduced shell, or has a small internal shell...
s and snail
Snail
Snail is a common name applied to most of the members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word is used in its most general sense, it includes sea snails, land snails and freshwater snails. The word snail without any qualifier is however more often...
s do not seem to bother it.
The thick, irregularly-shaped seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...
s should be planted just after the last spring frost
Frost
Frost is the solid deposition of water vapor from saturated air. It is formed when solid surfaces are cooled to below the dew point of the adjacent air as well as below the freezing point of water. Frost crystals' size differ depending on time and water vapour available. Frost is also usually...
. Before planting, the seeds should be soaked for 12 hours in cold water, or 3 hours in warm water. Seeds should be planted 5–10 mm deep, and spaced 15–30 cm apart. The seedlings will emerge in 10–20 days, and it will continue to produce greens through the summer.