Climbing pandanus on coastal dunes of the Tomaree Peninsula

Pandanus tectorius is best known across tropical northern Australia, where it forms dense thickets along the Queensland coast and in the Northern Territory. It is less familiar to walkers in the Tomaree region of New South Wales, where its appearance on dunes is sporadic and frequently overlooked. The species has a remarkable capacity to adopt different growth habits depending on where it germinates and how the dune system shifts around it.

When a pandanus seedling establishes itself on a sand dune rather than a sheltered embankment, its architecture changes markedly. Instead of producing the tall, palm-like trunk with a candelabra of branches that is often pictured in field guides, the plant may sprawl horizontally, sending out long stems that ride the contour of the dune. This prostrate or climbing form is one of the most distinctive expressions of the species on the New South Wales coast.

Bushwalkers travelling between Fingal Bay and Shoal Bay sometimes come across these low, sprawling plants without recognising what they are. The long, sword-shaped leaves arch outwards from stems that hug the sand, and the plants can cover several square metres without rising more than a metre above the surface. The dune form of this pandan is a quiet reminder of how much shape can be shaped by the ground it grows on.

Botanical description and growth habit

Pandanus tectorius belongs to the family Pandanaceae, a group of monocots with woody stems and a distinctive prop root system. The leaves are arranged in dense tufts at the ends of branches, each leaf long, strap-shaped and edged with small sharp spines along the margins and the midrib. In the Tomaree area, the leaves are usually a slightly glaucous green, fading to a pale straw colour as they age and become weathered by salt-laden winds.

The trunk and branches are supported by a network of aerial roots that descend from the stem to the ground. In an upright tree these prop roots form a cone or skirt around the base of the plant, but in the dune form they spread outwards across the sand. The roots anchor the sprawling stem and trap wind-blown sediment, slowly building a small mound beneath the plant. Over many years this mound can become colonised by other dune species, which then stabilise the surface further.

Fruits of Pandanus tectorius are large, segmented, pineapple-like aggregates that turn from green to orange or red as they ripen. They are rarely produced on the dune-climbing forms seen around Port Stephens, perhaps because the plant invests its energy in vegetative spread rather than reproduction in this exposed habitat. Where fruits do appear they are an important seasonal food source for native rats, flying foxes and some coastal birds.

Dune adaptations in a temperate setting

The dunes along the Tomaree Peninsula are dynamic environments, shaped by westerlies, sea breezes and occasional cyclonic swells. Sand moves constantly across the surface, and the vegetation that survives here must cope with burial, salt spray, drought and nutrient-poor substrate. The climbing pandanus responds to these pressures by staying low, extending its stems along the lee side of foredunes and sending roots down wherever a node finds stable sand.

This growth response is not unique to the Tomaree coast. Across the Indo-Pacific, Pandanus tectorius is recognised for its phenotypic plasticity, the same species producing very different forms in rocky headlands, freshwater swamps and coastal dunes. In each setting the root system and stem architecture adjust to the conditions, and the dune form represents one extreme of that plasticity. Local observers on the Tomaree Peninsula have noted plants that have grown horizontally for several metres before turning upward at a buried node, as though the dune has been gradually burying the original leader.

The climate of Port Stephens is markedly cooler and drier than the tropical strongholds of Pandanus tectorius. Winter frosts are absent near the coast, but summer rainfall is unreliable and the sandy soils drain rapidly. The dune form tolerates these conditions by reducing its leaf area relative to its stem length, and by relying on the moisture retained beneath the sand surface. Plants established under the lee of a headland or a driftwood log tend to fare better than those on open foredunes, where sand abrasion removes older leaves and exposes the stem.

The climbing form explained

The term climbing pandanus refers to the way the plant uses surrounding vegetation, driftwood or the dune face itself as a support. Unlike true vines, the pandanus does not twine or produce tendrils. Its stem simply leans against an obstacle, and once it has rooted at a node it becomes anchored in a new position. The original stem may then die back, leaving a series of clonal plants strung along the dune.

This pattern of growth is sometimes called a straggling or rambling habit. In the Tomaree context, plants often begin life under a coastal wattle or a sea grape, and then extend beyond the canopy of their nurse plant into the open sand. The exposed portion of the stem produces clusters of leaves at intervals, each cluster marking a point where the plant could potentially send down roots. Where the sand is stable enough, those roots establish, and the pandanus becomes effectively a chain of interconnected individuals.

Some older dune specimens around Nelson Bay show clear evidence of this process. The main stem may be partly buried, with several leafy tufts rising from it at different points along its length. A casual observer might mistake the arrangement for several separate plants, when in fact it is a single genet that has spread by layering. The same behaviour is described for pandanus populations on Queensland beaches, although the scale of the dune form in New South Wales is generally more modest.

Habitat on the Tomaree Peninsula

The Tomaree Peninsula stretches south from Nelson Bay and includes a range of dune, headland and bushland environments. Climbing pandanus is recorded sporadically along the coast, particularly where residential development has not removed the original vegetation. Established plants can be found near the edge of the national park at Fingal, and there are occasional records from the dunes between Shoal Bay and One Mile Beach.

For readers interested in the broader vegetation of the headlands, the Tomaree National Park flora includes a wide cross-section of coastal species adapted to similar conditions. Bushwalkers following the coast track from Birubi Point to Stockton Bight will pass through dune, heath and scrub communities in close succession, and any pandanus encountered in that stretch is most likely the climbing dune form.

The species is treated by some local reference works as an occasional rather than a core component of the dune flora, and it appears among records of introduced plants for the region. This classification reflects the fact that Pandanus tectorius is native to tropical Australia and is considered to have expanded its range southward, possibly with the assistance of birds and occasional garden plantings. Its presence on the Tomaree coast is therefore a useful case study in how a plant's status as native or introduced can shift depending on the region being discussed.

Identification features for bushwalkers and students

Identifying the dune form of Pandanus tectorius requires attention to several features that distinguish it from similar-looking plants. The spiny leaf margins are a reliable starting point. The leaves of coastal grasses and lilies may be strap-shaped, but they rarely carry the rows of small reddish spines that run along the edges and underside of pandanus leaves. The leaf arrangement is also distinctive, with leaves spirally clustered into tight tufts at the ends of branches or along the sprawling stem.

The prop roots are another useful clue. Few other dune plants on the Tomaree coast produce thick, woody aerial roots that descend from the stem to the sand. Pandanus roots are pale when young, darkening with age, and they often branch into the substrate at a shallow angle. Where a plant has produced a fruit, the segmented orange head is unmistakable and not easily confused with anything else in the local dune flora.

For students preparing herbarium specimens or photographic records, it is worth photographing the whole plant as well as close-ups of the leaf base, the prop roots and any flowers or fruit. The Nelson Bay Native Plants site accepts such records for inclusion in the regional photographic reference, and contributing images helps build a clearer picture of where the dune form occurs along the peninsula. PlantNET can also be consulted for confirmation of identifications and for updated distribution maps.

Ecological role and management considerations

Climbing pandanus contributes to dune stability in a small but meaningful way. Its sprawling stems and prop roots trap sand and organic debris, and the microhabitat created beneath its leaf tufts shelters invertebrates and small reptiles. Fallen leaves decompose slowly in the dry sand, adding organic matter to what would otherwise be a very impoverished substrate. Over time a single plant can create the conditions for other species, including spinifex and beach spinifex, to establish in its lee.

The species also has cultural significance. Aboriginal communities across northern Australia have long used pandanus leaves for weaving mats, baskets and dilly bags, and the ripe fruit segments have been an important traditional food. While these uses are not part of the contemporary economy of the Tomaree Peninsula, the presence of the plant in the landscape connects the local dune system to a much broader cultural and ecological story across the continent.

Management of climbing pandanus on the Tomaree coast is generally light-touch. The plants are not considered a significant weed threat, although their status as a non-core local species means they are sometimes monitored for spread. Residents who find a pandanus establishing in a backyard dune are usually encouraged to leave it in place, both for its stabilising function and for its interest as an example of a tropical species at the edge of its range. Walkers who would like to see the dune form in context can find further information in the entry on Tomaree headland flora.