Common Name: Australian Nut Palm

General Information

Cycas media is a cycad, growing up to 3 metres, occasionally to 6 metres, tall[]. A rather palm-like appearance, producing usually unbranched stems topped by a rosette of leaves each 70 - 180cm long[].
Although poisonous when raw, the seed is an important item of food for the Australian Aborigines, who collect them in large quantities throughout the year, using various means in order to remove the toxins, before cooking and eating them[].
Populations are believed to be stable, though there is habitat loss in some areas where the land has been cleared for cattle pasture. The plant is classified as 'Least Concern' in the IUCN Red List of Threatened Species(2011)[].

Known Hazards

The seeds are considered to be poisonous if eaten raw[].
We have no further specific information for this species, but most if not all members of this genus are believed to contain toxins. The two main toxic compounds that have been identified are cycasin and macrozamin. When ingested in sufficient quantities, these compounds are extremely poisonous to humans and many other animals, and have been shown to cause liver damage and cancer. Cycasin and macrozamin have a cumulative effect upon the body and are suspected of causing neurological disorders when ingested in small amounts over long periods of time.
There is a long history of human use of this genus as a starch-rich food, but it should be noted that the plants needed to be treated in various ways in order to remove any toxic principles. Caution should be exercised even with properly prepared foods, since even then regular consumption may lead to severe health problems and death. Since many of these species are becoming increasingly rare in the wild, this is probably a food best left to times of food shortage when other, better foods, are not available[, ].

Botanical References

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Range

Australia - eastern coastal Queensland.

Habitat

Widespread and locally common in open or closed forest or occasionally rainforest[]. Tall eucalypt forest or among shrubs, found in soils that vary from sands to gravels and loams at elevations from sea level to 860 metres[].

Properties

Conservation Status	Least Concern
Edibility Rating
Other Uses Rating
Habit	Evergreen Shrub
Height	3.00 m
Growth Rate	Slow
Pollinators	Insects
Cultivation Status	Wild

Cultivation Details

Cycas media is native to the tropics of eastern Queensland, often near the coast. It grows in a region where summer temperatures average around 20 - 30°c and the annual rainfall averages around 1,500 - 2,000mm, falling mostly in the summer[].
Usually found on sites that offer good soil drainage, often on sandy soils and on sloping sites. An almost universal requirement for cycads is a well-drained but moisture-retentive soil, and by far the best soils are sandy gravels and light loams which provide the required drainage and aeration necessary for good growth. Cycads will generally not grow well in clay soils unless those soils are heavily amended with sand and organic matter[]. A neutral soil (pH 7), is generally best for most species of cycads and allows the proper absorption of nutrients. A slightly acid soil is better for most cycads than a basic one[].
Species in this genus can usually be transplanted easily even when quite large. The best time for moving them is just before the beginning of a new growing season, the roots being trimmed if they are damaged and perhaps some leaves being removed. New roots should develop quickly as the season progresses[].
The plant is often found in areas where fires occur most years. Although the leaves and cone are burnts, the plant quickly recovers and produces new cones[]..
Species in this genus form structures known as coralloid roots. These roots branch off from the taproot or secondary roots and are distinctive in that they grow laterally or upward, forming a nodular mass at the apex. These coralloid roots occur slightly below or slightly above the soil surface and generally contain cyanobacteria, also known as blue-green algae. These are able to fix atmospheric nitrogen and make it available as a nutrient to the plant. The ability to extract this important nutrient from the air explains how many cycad species are able to survive on almost sterile soils[].
A dioecious species, with individual plants producing either all male or all female cones. Therefore both male and female forms of the plant need to be grown if seed is required[]. On very rare occasions, usually when a plant has been under severe stress, it can change sex and produce either all female or all male cones[].

Edible Uses

Although considered to be poisonous when fresh, the seeds are roasted, then pounded several times and consumed as food[].
Traditionally, in order to remove any toxins, the seeds are roasted in a fire, and then left in the ashes until the next day. The shells are then removed and the kernel ground into flour. This flour is then put into a cloth sack and left to wash in a running stream for another day before being eaten[].

The starch obtained from the pith of the stems was at one time extracted on a commercial basis[].

Medicinal

None known

Other Uses

A starch obtained from the stems can be used as a laundry starch, to make adhesives etc[].

Propagation

Seed - best sown in containers as soon as it is ripe. Stored seed should be pre-soaked for 24 hours in warm water prior to sowing. The seed should be sown 2cm deep in individual pots, which are then sealed in plastic bags to keep them moist until germination takes place. Germinates in 1 - 3 months at 25°c[].
Division of suckers[].

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