The vegetable Australia gave the world

By Tim Low 17 October 2017
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The first Australian food to be cultivated abroad was a seashore spinach.

WHEN BRITAIN was deciding if Australia was a suitable outpost for convicts a native vegetable was touted as one of the advantages.

The botanist Joseph Banks, who visited Australia with Captain Cook, spoke of ‘wild spinage’ when called before a House of Commons Committee to discuss the merits of Botany Bay. He mentioned luxuriant grass and edible vegetables, of which the ‘spinage’ was singled out.

Against strong competition from West Africa, Australia gained the convicts, and the free ‘spinage’ promised by Banks may have helped sway the vote. The plant in question is New Zealand spinach (Tetragonia tetragonioides), known also as wild spinach and warrigal greens, a plentiful plant of Australia’s seashores and fertile inland woodlands.

Captain Cook and Banks encountered it first in New Zealand, and later at Botany Bay, and the captain had it served as a scurvy treatment, although it appears to lack vitamin C. Banks considered the plant to “eat as well as spinage or very near it”. Seeds he took to England were propagated in Kew Gardens, and seeds from there went to Europe and North America where, as ‘Botany Bay Greens’, they were sold in catalogues as a hardy summer-growing spinach. The plant remains in cultivation around the world without being especially popular. To Sydney’s convicts it proved a useful vegetable.

Australian spinach

New Zealand spinach. (Image Credit: Kim Starr/Wikimedia)

New Zealand spinach is important these days to the bush foods industry, but the main name it acquired poses a marketing problem, so it is promoted under an old and obscure name, ‘warrigal greens’.

It is native to China, Korea and Japan as well as Australasia, but Australia appears to be its original home. A recent genetic study indicates an African origin for the family it belongs to (Aizoaceae), but points to genus Tetragonia evolving in Australia, producing about nine species here, and colonising other parts of the world, including South America and Africa. As with many seashore plants the seeds float, and the prevailing east-flowing currents carried them to Lord Howe Island, New Zealand and further afield.

The history behind one Tetragonia is unusually impressive. Sea spinach (T. decumbens) is an African plant that became a weed on Australian beaches after its seeds travelled across on ships. If we reconstruct the journeys of its ancestors a circumnavigation of the globe is implied, and more. The family arose in Africa, one species reached Australia and evolved into Tetragonia, then one of its descendants floated back to Africa, spawning sea spinach, which then ‘returned’ to Australia on ships.

Warrigal greens deserves a place in everyone’s garden. If anything, it is better than real spinach (to which it is unrelated), because in stir-fry dishes it handles heat better. I often cook it in spanakopita, and it serves well in pesto. It is very easy to grow. Next time you visit the beach, see if you can find a plant with seeds, or order some online.