AUSTRALASIAN Tropical & Subtropical Moist Broadleaf Forest
Plants

The plants of the rainforest in tropical Australia, New Guinea and the surrounding islands...

Kingdom Plantae

Class Polypodiopsida: Ferns

Aspelnium nidus, 'Bird's Nest Fern'. Grows on trees as an epiphyte, also often found growing on rocks.

Platycerium spp., 'Antler Fern', 'Staghorn Fern'. About 18 species. The genus is found in tropical forests around the world.

Order Laurales
Family Hernandiaceae
Family Lauraceae
Order Magnoliales
Family Myristicaceae
Family Eupomatiaceae
Order Piperales
Family Piperaceae 

Order Arecales

Family Arecaceae: Palms

Ptychosperma macarthurii, 'Macarthur Palm'. Found in rainforest in pockets of N.T, and New Guinea and south-west Pacific islands.

Order Asparagales

Families Amaryllidaceae

This group contains a range of ornamental plants, such as the various daffodils, and the ‘crinum lilies’ (the ‘true lilies’ are in a different order). It includes several species that provide vegetables and flavours, such as chives, leek and onion.

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Crinum pedunculatum , ‘Crinum Lily’, ‘Mangrove Lily’. Short shrub. Large, long leaves with longitudinal veins. These clasp around a short stalk. Produces a stalk with an umbel of many white, spider-like flowers, giving rise to other common name of ‘spider lily’. Fruits are unusual, almost onion like; green and round, with elongated pipes at end. These split to drop angular semi-circular seeds that are a green- tinged white with an almost styrofoam like surface. They are ocean dispersed, and thus sometimes seen washed up on tropical beaches. Indigenous uses include the crushed up plant used to alleviate box jellyfish stings, and fibrous parts of plant trailed behind moving boat as a lure to catch fish such as mackerel. Usually found only at sea level, and in wet forest, on edge of mangroves, and behind beaches along subtropical and tropical east coast of Australia, across the top to the NT, to New Guinea and other tropical Pacific Islands.

Family Orchidaceae

Spathoglottis sp.

Order Commelinales

Family Philydraceae

Helmholtzia glaberrima, 'Stream Lily'. Found along freshwater streams in rainforest in north-east NSW and south-east Queensland. A very obvious and striking  plant when it produces its large heads of pink flowers.  

Order Liliales

Family Smilacaceae

There are at least 300 species in this family, and they are found throughout the tropics of the world, as well as in many temperate areas. 

Smilax spp.

In Australia, they are sometimes more obvious in subtropical forests, but there are a couple of species that can be found along the wetter tropical coasts. They can grow as vigorous climbers, with the wiry, curling tendrils growing in pairs from the petiole at the base of the leaves. Their leaves are easy to recognize, as they usually have 3 to 5 prominent veins. The fruits grow in umbels  They can be annoying plants because the main stems are covered in small prickles. Several smilax vines provide the original Sarsaparilla

Order Pandanales
Family Pandanaceae
Order Poales
Family Flaggellariaceae
Family Poaceae

Order Zingiberales

Family Costaceae: Spiral Gingers

Tapeinochilos spp. 'Back-scratcher Gingers' 

Tapeinochilos sp. 'Back-scratcher Ginger', 'Pineapple Ginger'. 

Family Zingiberaceae

Order Proteales

Family Protecaceae

Mostly a family of plants found growing in sandy soil heathlands in southern Africa and south-west Australia, but with some interesting species in the rainforest along the east coast of Australia, including some of the dominant canopy trees.

Alloxylon spp. 'Waratah Trees'

There are four species in this genus, found in rainforest along the east coast of Australia and north into New Guinea.

Alloxylon pinnatum, 'Dorrigo Waratah Tree'. Found in subtropical rainforest in south-east Queensland.

Stenocarpus spp.

A genus of mostly trees and tall shrubs. Some 10 species are found in the subtropical forests along the east coast of Australia. but more are found and endemic to New Caledonia.

Stenocarpus sinuatus, 'Firewheel Tree' . Popular garden tree. Found in subtropical rainforest from NSW to the Atherton Tablelands in North Queensland.

Order Dilleniales 

Family Dilleniaceae

There are some 60 species of Dillenia found in tropical Asia and the Pacific. The large fruited ‘Elephant Apple’ is cultivated in gardens. There is only 1 species native to Australia.

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Dillenia alata ‘Red Beech’. Distinctive flaky red bark, large yellow flowers, and red fruits that open up like a flower to reveal the seeds. Common in coastal forest in Queensland and NT, and up into New Guinea, including on forest on sandy soils just behind beaches. Obvious at the Cape Tribulation picnic area.

Order Vitales 
Family Vitaceae
Order Fagales 
Family Casuarinaceae

Order Rosales

Family Urticaceae

Dendrocnide moroides, 'Stinging Bush', 'Gympie Gympie'. Small hairs on this plant cause extreme pain.

Family Moraceae

Order Celastrales

Family Celastraceae

This family has over 95 genera and over 1350 species. They are found worldwide, but there are many more species in the tropics and subtropics. The flowers are usually small and pale white or green, with 3-5 sepals and petals.

Salacia spp.

There are over hundreds of species in this genus, mostly in the tropics, with 3 species found in the tropical rainforest of North Queensland. The genus name Salicia, refers to the name of the wife of the ocean god Neptune in Roman mythology, part of the name which in turn came from the word for the latin word for salt.

Salacia chinensis, ‘Lolly Berry’. Grows as a vine. Opposite leaves. Named for the red, round fruits that look like lollies, have sweet, edible flesh, which is also sticky, requiring one to suck on the seed. This vine is often found on the edge of forest and mangroves along waterways and beaches, from tropical North Queensland, through the Pacific islands, across south-east Asia and to India.

Order Malpighiales

Family Achariaceae

Three species; with two in Asian rainforest and one in north-east Australia.

Ryparosa kurrangii, (Daintree, Australia).

Family Euphorbiaceae

This huge family has over 6000 species spread over 250 genera, making it the fifth largest family of plants. They are found throughout the world, from tropical areas to temperate. On a global scale, the huge range of different species has few easily identifiable features. In fact, it’s status as a true ‘monophyletic’ group (related species from a single origin) have long been in doubt. Recent research has confirmed these suspicions, and many species have been taken out and placed them into their own families. Locally however, many of the species in this family tend to have some features in common: they often have small not very colourful flowers, rounded or heart-shaped leaves, exudate or 'sap' when a branch is broken, and are commonly pioneer or edge species. There are over 150 species found in the Australian tropical rainforest.

Homalanthus populifolius, 'Bleeding Heart'. Tree or tall shrub. Named for the distinctive bright red heart-shaped leaves that are mixed in with the green leaves.

Macaranga spp.

This genus has about 300 species. There are half a dozen species found in Australia, and they are all found in association with tropical forests. Although there are many species in the Australasian rainforest with large heart-shaped leaves, this group is the one most commonly seen. One of the more widespread species throughout Australia and Asia is Macaranga tanarius, with a centrally attached stalk and yellow venation. Being a ‘pioneer’ species it grows on the edge of the forest and thus is easily seen along the side of the road. They are found throughout the Old World tropics, but are especially common and dominant in the rainforests of tropical Asia and the western Pacific Islands, where many of the heart-shaped leaved species have ecological relationships with ants.

Aleurites spp.

There are between 3 and 6 species in this small genus. They are found from tropical Asia, to New Guinea and islands of the south west Pacific, to Australia. There are 2 species in Australia, and both are found in the rainforest. They are commonly called ‘candlenut’, as the seeds have a high oil content and were used as candles.

Aleurites rockinghamensis, ‘Candlenut’. Huge heart-shaped leaves. Commonly seen fruit on the forest floor, especially in the mid altitudes, and often have holes chewed in them by white tailed rats. Aleurites moluccanna is similar to previous species, found from the Daintree and up into Cape York. Both species are found in New Guinea and tropical south-west Pacific Islands.

Order Myrtales

Family Myrtaceae

The family Myrtaceae is arguably the most important on the Australian continent, although they are not as obvious in the rainforests as they are in the adjacent woodlands.

The flowers in the Myrtaceae family are usually quite showy, but not in the usual way; instead of colourful petals, there is instead a seemingly unlimited number of stamens, giving the flower the appearance of a brush.

Botanists often divide the family into two different sub-families. One group are the ‘woody-fruited myrtles’. These are dominant in drier parts of our continent, and include the classic Australian genera such as Eucalyptus and Melaleuca. The other group, the ‘soft-fruited myrtles’ are usually associated with wetter environments and found mainly in the tropical rainforests of the Americas, Australia and parts of Asia and the Pacific. It includes such genera as Syzygium, Acmena and Eugenia, and are commonly known as the ‘Apples’, ‘Satin-ashes’ and ‘Lilly-pillies’ and usually produce fleshy, colourful fruits.

Eucalyptus grandis, 'Flooded Gum', 'Rose Gum'. (Atherton Birdwatching Lodge). Usually very tall and straight, with lots of large strips of peeling bark. Found along the east coast of Australia in wetter habitats, including being one of the few 'gum trees' in or on the edge of the rainforest.

Family Melastomataceae

Probably Melastoma malabathricum.

Order Caryophyllales

Family Nepenthaceae

Nepenthes misool sp. 'Misool Pitcher Plant' (Misool, Indonesia)

Family Rubiaceae

Morinda spp.

There are at least 50 species in this genus throughout the tropics of the world, with 10 species found in the forests and woodlands of Australia. They can be climbers, shrubs or trees. The tiny flowers develop into large aggregate fruits. Some species have strongly unpleasant smelling flowers or fruits. The fruit is also collected and eaten by many indigenous people, including Australian aboriginals.

Morinda citrifolia, ‘Cheesefruit’ ‘Great Morinda’. Small tree. Large, glossy leaves, strong venation. Fruit foul smelling, like rancid cheese (wrapped in old socks), but edible. However, don’t keep any specimens in your backpack and forget about them (like someone I know did. OK, it was me.) The species known as ‘Cheesefruit’ is cultivated on many islands of the tropical south Pacific, where it known as 'Noni'. Some samples of the fruit tested much higher for vitamin C than oranges.

'Ant Plants'

One of the most unusual members of the Rubiaceae family are the ‘ant plants’. These strange looking bulbous plants are epiphytes, and can be found growing on the branches of trees in mangroves, Paperbark wetlands, and tropical rainforest. They are so named for housing ant colonies within their main swollen stem. Some observations have noted other insects living within the plants. They are found from tropical Asia, through New Guinea, to Australia and some Pacific islands.

The genera include: Anthorrhiza, Hydnophytum, Myrmecodia, Myrmephytum, and Squamellaria. The genus Anthorrhiza contains about nine species and is endemic to New Guinea. The genus Hydnophytum contains between 55 and 90 species found across tropical Asia and into Australia, but with a centre of diversity in New Guinea. The genus Myrmecodia contains about 27 species, and they are found mostly in south-east Asia, but also through New Guinea, the western Pacific Islands and into tropical Australia, with 3 species found in the latter region. The genus Myrmephytum contains five species found in south-east Asia and New Guinea. The genus Squamellaria contains just four species; they look like spikey balls and are endemic to Fiji. 

 In Australia, ant plants can easily be seen along Marrdja boardwalk, on the north side of the Daintree River ferry crossing and in the Cairns Botanical Gardens.

Family Loganaceae
Family Solanaceae

Family Bignoniaceae

Deplanchea tetraphylla, 'Golden Bouquet Tree'. Lowland rainforest along coast. From North Queensland, through cape York, and into New Guinea.

Family Verbenaceae
Family Araliaceae

A video on how to deal with the dangerous plants of the Australian rainforest... 

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