The desert yam (Ipomoea polpha ssp. latziiu) is a very rare perennial plant occurring only in a small area in the northern quarter of Central Australia. It is known in adjoining areas both by reputation and as a central part of the indigenous peoples’ dreaming. The plant is a trailing vine like plant with stems trailing up to 4m on the ground. It has large rounded tubers that may weigh up to 2.6kg, specimens as large as a human head have been noted. It grows in Acaccia shrublands, on red earth soils, and occasionally on adjacent sandplains.
The desert yam has been a sought after food for many tens of thousands of years, especially for the Anmatyerr language group, although it also features in the Dreaming of the nearby Alyawarr language group. The desert yam is under threat partly because of its already extreme rarity, but also because the indigenous knowledge of its management is being lost. Changes in land and fire management plus the impact of introduced fauna – camel, rabbit and cattle are likely to see this plant disappear in the future.
The land management techniques practiced by indigenous people indeed involve fire, an element that has a crucial role in many aspects of these communities’ lives (environmental, social, cultural, spiritual…). Using controlled fires, a knowledge that is gradually lost, enabled for example to prevent hot incontrollable wildfires to develop, and helped biodiversity and the land to regenerate.
The desert yam was once a staple food of the Anmatyerr people. The large tubers were usually either cooked, in hot ashes or steamed, before being eaten. It has been regarded as the best of the Central Australian desert tubers because of its texture, flavour and high nutritional value.