Fruit & Vegetables Aussie Bush Tucker - An Introduction to Common Native Foods of Australia

Pandanus spiralis, Horseshoe Bay Beach, Bowen, Queensland. © JPM, 2022.

Names

Hailing from the genus Pandanus (P.), the 750-odd species of these plants have a myriad of names due to their overall tropical and subtropical global distribution and general importance and usefulness to human civilisation. Some English names are from south-east Asia; the common name pandan comes from Malay, where the plants are also prolific (especially P. amaryllifolius, origin of the 'Vanilla of Asia' pandan leaf). Other common names include screwpine, screw palm, wynnum (south-east Queensland) and the Hawai'ian hala (in New Zealand, Maori whara or hara) is also a fairly common name for the plant. Despite these names, pandanus are not related to either palms or pines, being instead a type of monocot (grass).

Specific to Australia, there are three prominent native species. P. spiralis is the most iconic and easily recognised as the screwpine; P. tectorius is equally prominent along much of Australia's eastern, tropical and sub-tropical coastline and probably best simply called native or coastal pandanus. A Top End variant, P. basedowii, is one of the more prominent plants in parts of Kakadu and the Kimberley. There are a few other less common Australian species such as P. gemmifer (pup pandanus), known for its abundant 'pup' shoots, P. aquaticus (water pandanus) and P. cookii, common in Cape York, amongst others such as P. forsteri and Christmas Island's P. christmatensis.

Habitat and Range

Pandanus is generally a littoral (coastal) plant, often found right at the beach front in prime, scenic positions. Pandanus spreads via floating fruit segments, making its way across entire oceans in this manner; seeds take up to 12 months or more to germinate i the segments. They also happily occupy rock outcrops, islands and coral atolls, and can make their way inland into river valleys, lakes and lagoons. Some places, like Papua New Guinea, Malaysia and Madagascar, pandanus can be found up to elevations of 3,300m (10,000 ft) in tropical or sub-tropical rainforest settings. In many places where they occur, pandanus has been cultivated and expanded by humans for millennia, often by planting cuttings. Pandanus demands full sun; where full sun is lacking, the plant will actively warp and wend its way to find it! Pandanus cannot tolerate cold or frost, so it is mostly absent from the frost-prone interior and temperate coasts.

In Australia, the screwpine (P. spiralis) is found mostly in the Top End, from the Kimberleys, Kakadu, across the Gulf of Carpentaria and throughout Cape York and scattered down the north-eastern part of Queensland at least as far as Airlie Beach. The coastal pandanus (P. tectorius) occurs mostly on the eastern coast, from Cape York as far south as Port Macquarie and Taree. The Kakadu pandanus (P. basedowii) is found west of Arnhem Land in generally difficult to reach, crocodile-infested canyon and escarpment country. The other less common species are found dotted across the Top End, Gulf country and Cape York, with P. aquaticus particularly preferring to grow in wholly fresh-water environments.

Figure 1. Distribution of Pandanus (all species) across the continent. Atlas of Living Australia.


Identification

Key Identifying Features

• Ridged, scarred and/or knobbly trunk wood
• Aerial stilt roots (may be absent in P. spiralis)
• Multiple trunks/branches on older plants, 5-12 m tall, which themselves may exhibit aerial stilt roots
• Foliage grows in a helix around the trunk
• Foliage is generally long, 1-4 metres, and fibrous
• Foliage has sharp, serrated edges
• Green foliage has a white base when removed from the trunk which tastes sweet and fragrant, like sugarcane and vanilla
• Dead foliage may drape from the trunk or branch like a palm
• Fruits are large, 3-7 kg, and segmented into dozens of hard, knobbly pineapple-like pieces
• Fruits are green unripe, turning yellow, orange or red when ripe
• Ripe segments fall to the ground
• Ripe segments have a soft, juicy base and hard, knobbly tip
• Tropical, sweet-smelling juice can be squeezed out of the soft segment base with the fingers
• Segments can be cut open to reveal slender, white seeds tasting like coconut

Pandanus are very distinctive plants where they occur, with older, established specimens looking somewhat like palms, especially if older leaves still adorn the trunk and have not been burned or blown away (see header image above). Unlike palms, however, pandanus may grow multiple trunks and branches.

Figure 2. Multiple trunks and branches on a coastal pandanus (P. tectorius), thus distinguishing it from any kind of palm tree. Alma Bay, Magnetic Island. © JPM, 2022.


Figure 3. Multiple trunks on a young P. gemmifer, amidst dozens of spawning 'pups'. The Palmetum, Townsville. © JPM, 2022.


Trunks and branches often exhibit scarring from dropped leaves, similar to the way palms leave behind distinctive ribbed patterns. Main trunks will also form distinctive, sometimes pyramidal, aerial stilt roots at the base. These stilt roots may also form from low branches, an indicator that those branches may be lopped and planted as cuttings themselves.

Figure 4. Ribbed and knobbled trunk of an established coastal pandanus (P. tectorius). Wikimedia Commons. © F. & K. Starr, 2004.


Figure 5. An example of stilt roots on a coastal pandanus (P. tectorius). Alma Bay, Magnetic Island. © JPM, 2022.


Figure 6. Stilt roots on P. forsteri. Note that some of the roots on this specimen emerge from the branches as well as the trunk. Atlas of Living Australia. © D.H. Fischer, 2009.


Leaves grow in a helix pattern around the trunk, a feature which is especially prominent for the screwpine (P. spiralis). Other species, like P. tectorius, may be too tall to observe this feature. Leaves are long, usually 1 to 4 metres, strappy and have sharp, saw-blade edges similar to pineapple. Leaves broken off the plant while green will also exhibit an edible white leaf base. Some species may exhibit a 'channel' in the centre of the leaf, running its whole length along the central vein.

Figure 7. The spiraling, helical foliage of the screwpine (P. spiralis) is very distinctive. Alma Bay, Magnetic Island. © JPM, 2022.


Figure 8. Closeup of a screwpine leaf (P. spiralis), showing the sharp, saw-blade edge and channel. Alma Bay, Magnetic Island. © JPM, 2022.


Figure 9. The edible, white leaf base of P. christmatensis, the Christmas Island pandanus. Atlas of Living Australia. © M. Fagg, 2012.


Pandanus are dioecious plants, meaning they have distinct male and female genders. Only female plants will develop fruit, which look like giant, knobbly pineapples with dozens of distinct segments. Fruit can take between 1-2 years to ripen, turning from green to a vibrant yellow, orange or red. Individual fruit segments will fall from the tree to the ground when they are fully ripe and will emit a pleasant, 'tropical' fruity scent.

Figure 10. Male flower on coastal pandanus (P. tectorius). Wikimedia Commons. © F. & K. Starr, 2021.


Figure 11. Female flower on P. montanus. I had great difficulty sourcing photography for female flowers. Wikimedia Commons. © Céréales Killer, 2006.


Figure 12. Fruit of coastal pandanus (P. tectorius) demonstrating unripe and ripening specimens. Atlas of Living Australia. © Wingspanner, 2022.


Figure 13. Orange-red fruit of P. gemmifer, the pup pandanus. Atlas of Living Australia. © Coenobiter, 2018.


Figure 14. Very ripe fruit of P. cookii. This example has begun to drop its segments. Atlas of Living Australia. © R. Cumming, 2022.


Figure 15. Individual segment from a coastal pandanus (P. tectorius). This segment had fermented in my bag for a few days before I brought it home, but it made the soft, juicy end (brown, left) very distinct from the hard, knobbly seed end (yellow, right). Acquired from Horseshoe Bay Beach, Bowen, Queensland. © JPM, 2022.


Uses

Pandanus ranks the second most important plant, behind coconut, for many island civilisations of the Indo-Pacific. As a food, pandanus may be harvested for its leaf or its fruit. While the Malay species, P. amaryllifolius, is properly referred to as the spice, pandan leaf, Australian species also have edible leaves but not quite packing the fragrant punch of the millennia-cultivated Malay species. Pandan leaf is the star of the Malaysian dish nasi lemak. Any pandanus leaf may be pulled from the plant and the white base chewed; it is fragrant and refreshing. Fresh leaves can be torn into strips and bundled together and thus used as the spice, pandan, to flavour drinks, soups, curries, cakes, jellies, icecream and steamed rice, although not quite as well as the Malay species already described. Pandan leaves are oddly high in iron, making them an important source of that nutrient for vegetarians.

Pandanus fruit will soften near the base (see figures 14 and 15 above) when fully ripe, especially in the days after falling from the tree. A sweet, tropical-scented juice can be squeezed or sucked directly from this fibrous part, although caution must be taken when consuming this raw (see below). Whole segments were traditionally flame roasted, which makes the tough fruit fibres brittle. Roasted fruit can thus be split apart with an axe or hacksaw (do not use a stone unless you have a few hours to waste) and the skinny, white seeds extracted and eaten. First Nations people of the Top End used a traditional iron tool made from metal traded from Indonesian pearl divers called a djin-garn-girra to prise the seeds from the tough, hard fibres they are so tightly nestled inside. Other traditional tools for this purpose were made of bone, hardwood or stingray tail spines. Nowadays a vice and a metal hacksaw gets the seeds out in less than 5 minutes. The process needs to be repeated to extract all the seeds. The seeds taste like a mild version of coconut and the flavour is improved with roasting.

Figure 16. Pandanus segment halved by hacksaw, exposing the slender, white seeds in the hard portion (dark brown part). I originally attempted this with a super-sharp meat cleaver, which got stuck fast inside the hard part of the fruit on the first strike! © JPM, 2022.

Pandanus has a myriad of other uses besides culinary ones. Its leaves are long and fibrous, making them excellent for all kinds of weaving: basketry, mats, hats, bags, skirts, roof thatch and even sails; pandanus leaf was the traditional material used for outrigger canoe sails by many traditional Pacific island mariners in their intrepid voyages. Aerial roots, often being straight, make good poles for construction of huts. The fragrant male flowers of the subcontinental species P. odorifer, common in the Bay of Bengal region, are used in some places as perfume, or distilled into the fragrant essential oil called kewra (or kewda/keora).

Figure 17. Phillipino 'bayong' basketry using pandanus leaves. Wikimedia Commons. © Alma Gamil, 2012.

Figure 18. A pandanus-fibre crab-claw sail of Solomon Islands design on a 'tepukei' outrigger canoe. Wikimedia Commons. © Bin im Garten, 2011.


There are traditional medicinal uses for the plant in many cultures which I will not cover here.

Caution - Oxalates!

Tim Low (Wild Food Plants, pp.42-43) mentions the fruit juice of some Australian species, or indeed individual plants, being extremely irritable to the human palate when consumed raw. Some early European explorers who had suffered ill effects after eating raw pandanus juice marvelled that First Nation tribes, particularly in the Top End, were able to consume some fruit raw. While Low supposed, incorrectly, that human immunity may have been a reason for the difference, the truth rests in the fact that some species, or individual tree specimens, exhibit fruit and juice which is high in calcium oxalate (see Michael A. Arnold [2014], "Pandanus tectorius S. Parkinson" [Pdf LINK]). Consumed raw, juice from some plants will result in the explorers' experience of blisters on the lips and tongue, nausea, vomiting and diarrhea, while other pandanus plants in the same area lacking this toxin may be eaten raw with gusto.

I suspect that ages of tradition led individual tribes to identify pandanus plants in their local lands which exhibited low or no oxalates (not that they knew the chemistry), making them safe for raw consumption for those in the know. The Asian and African cultivars P. amaryllifolius and P. utilis are examples of generally low oxalate species, but this can vary from plant to plant. Generally, the larger the whole fruit, the lower the oxalate content; the smaller the whole fruit, the greater the risk of higher concentrations of this irritant.

Because we do not generally possess such streams of tradition to guide our choice of plants when out wild foraging, notwithstanding foraging alongside a local lorekeeper, it is recommended that any pandanus juice be extracted from ripe segments only after first cooking the segments by roasting or steaming. Heat treatment will break calcium oxalate bonds and render the poison inert and safe to eat. Virtually all pandanus seeds are safe to eat, raw or cooked, regardless of calcium oxalate levels in the fruit juice.

Lastly, the serrated edges of pandan leaves are very sharp, easily leaving deep 'paper' cuts in human skin. Harvest with care and wear gloves and long sleeves if necessary!