Category: Rainforest Trees

(Black Bean, Moreton Bay Chestnut)

Since coming to Cairns from Paluma, I am learning to identify a slue of plants and birds endemic to this region of the tropics.  One rainforest tree however, was familiar to me, as it would be to most North Queenslanders: the Black Bean, or Castanospermum australe.   It is native to the east coast of Australia in Queensland and New South Wales and to the Pacific islands of Vanuatu, New Caledonia and New Britain.   The Castanospermum belongs to the Fabaceae family and has the distinction of being the only species within the genus Castanospermum.

It is a handsome tree, growing up to 35 metres with fairly dense foliage of compound leaves, but the brilliant vermilion and yellow sprays of pea-like flowers are what make this tree so spectacular around this time of year, (September-October).  It was a bright carpet of dropped flowers beneath the tree that drew my attention to it.  The flowers are followed between March and May with large pods which split to reveal 2 to 3 large brown seeds weighing about 30 grams each.  The canoe-shaped pods are easily recognised.   The seeds are hairless and reminiscent of chestnuts and look quite appetising; but woe betide anyone who samples one that has not been properly prepared.

The seed is highly toxic.  Sulphur-crested Cockatoos eat them but I know of nothing else that does so. Eating one causes vomiting, diarrhoea, severe abdominal pain and dizziness and can be serious if urgent medical attention is not sought.  Sawdust from this tree can cause dermatitis, eczema and nasal irritation.  The leaves and seeds are poisonous to live-stock.  

However, the seed is a highly nutritious food source and the Indigenous people of the North Queensland coastal rainforest devised a sophisticated way of rendering the seeds safe to eat.  This involved a sequence of steps which include, roasting the seeds overnight in a ground oven, slicing and mashing, placing in a dilly-bag to leach in running water, and finally pounding the seeds to a flour-like powder.

As far as I know, the poisonous compound in the Black Bean is as yet, unknown.  Many of the rainforest trees have chemicals which could potentially be used medicinally and the Castanospermum was mooted as containing chemicals which could be used against AIDS.

Text & Photos by Colwyn Campbell

The native hydrangea (Abrophyllum ornans) is a small understorey tree (up to 8m high) or shrub that is endemic to Qld and northern NSW. It can be found in rainforest gullies and streams or regrowth areas from Batemans Bay to the McIlwraith Range NE of Coen in Cape York. The Genus Abrophyllum belongs to the family Rousseaceae, which is restricted to New Guinea, Australia New Zealand and Mauritius.

The scientific name refers to its attractive leaf and is derived from the Greek habros (splendid) + phyllon (leaf) and the Latin orno (adorn).

The bark of the native hydrangea is grey or light brown. The alternating leaves are ovate with pointed tips and finely serrated edges (up to 2ocm long and .8 cm wide).

• 

• 

• 

• 

Small perfumed whitish yellow flowers develop in branched clusters from October to December and the unopened buds can resemble true Hydrangea flower heads (although the two species are not related). Flowers develop into distinctive purple to blackish berries about .5cm in diameter.

A. ornans is cultivated as a garden ornamental, valued for its handsome clusters of berries, or as an indoor plant. It is easily propagated from cuttings or fresh seeds. It is also considered a useful plant for restoration along rainforest edges.

Text by Jamie Oliver
Photos (unless indicated) by Russell Cumming on Flickr

Although the rainforest around Paluma is extensive, covering over 42km², it forms a narrow north-south band that changes to eucalyptus dominated sclerophyll forest as one travels east down the range or west towards Hidden Valley. The border between rainforest and sclerophyll forest is not fixed, and some studies have shown that the rainforest is slowly expanding and encroaching on the ecologically important sclerophyll habitats that host a number of important species of plants and animals. Late last century there was concern that rainforest expansion might be an ecological threat to adjacent forests but more recent work shows that the rate of expansion is very low, and current climate predictions for destructive cyclones and increased bushfire severity in the region suggest that rainforests are the more threatened of the two habitats.

Some evidence of past rainforest encroachment can still be found along some walking tracks, where there are huge old Eucalyptus trees that would have germinated in open forest have survived the fierce competition for light that characterises rainforest habitats and now stand as anomalous reminders border dynamics. This series has already highlighted two sclerophyll trees that can be found near rainforest margins (Eucalyptus grandis and Syncarpia glomulifera). A third species is the Messmate (Eucalyptus cloeziana).

The track down to Triple Falls from the H-track has some magnificent old messmate trees in an area just adjacent to open forest at the crest of the escarpment. This tree is endemic to eastern Queensland and in ideal conditions can grow to 55m in height. The lower trunk has rough flakey or fibrous bark, but is smooth on the upper trunk and branches. Leaves are lanceolate to ovate 0.2-1.3cm long. Flowering occurs has been recorded in December and January. The mature gum nuts are globose to hemispherical, 0.4–0.7 cm long, 0.6–1.1 cm wide.

Messmate has been logged over most of its range and is now cultivated in plantations. It has been imported to Africa and is one of the more important general purpose hardwood plantation trees in Zambia and Zimbabwe.

The species name (cloeziana) was chosen in honour of Francois Cloez, a chemist who originally identified the chemical cineole as the major constituent of eucalyptus oil.

Text and photos (unless indicated) by Jamie Oliver

The buff alder (Apodytes brachystylis) is a common understory tree in well-developed rainforests from sea level to 1200m. The genus (around 8 species are recognised) is distributed from Africa through Asia to the western Pacific, but A. brachystylis is endemic to (found only in) north Queensland and is most common in upland rainforests from Cooktown to Townsville.

The leaves have a wavy margin and the leaf stems (petioles) are yellowish with a grooved upper surface. The flowers are small (petals 3-4.5mm long) with hairs on the inner surface.

• 

• 

None of these features make it easy to spot this species during a casual walk through the rainforest, however, once the fruit drops ) to the ground (November to February) this species is unmistakable. Usually what drops is a very handsome combination of a dark blue-black receptacle (the basal part of the flower) and a bright green carpel (the seed bearing structure that contains the ovaries, stigma and style).

• 

• 

Based on my frequent encounters with the fallen fruit on the tracks around Paluma it appears to be quite common around the village. There is a tagged specimen (White Tag Number 16) of the tree about 3/4 of the way down the slope toward the main plank bridge on the H-Track (starting from Whalley Crescent.

Text and Photos (unless indicated) by Jamie Oliver

The Hickory Boxwood (Planchonella euphlebia) is endemic to north Queensland. It is a widespread and relatively common tall (~25m), often buttressed tree in established rainforests from 200m to 1200m in altitude. It is also sometimes referred to as Pouteria euphlebia, although this name is now considered to be a synonym .

Leaves are obovate (egg-shaped with the narrow end towards the stem) and 5-14cm long. The undersides of young leaves are covered in fine brown hairs. the species name euphlebia refers to the well developed (“eu”) veins (“phlebius”) on the leaves.

Although common around Paluma, these trees are not easy to distinguish from the appearance of their trunks. There is a tagged specimen (White Tag number 10) on the H-track near the bottom of the slope leading down from Whaley Crescent. However the fallen fruit are easy to identify. The fruit appear from October to December and are fairly common on the ground along many Paluma walking tracks. They are about 1.5.2cm long. globular to elongate and coloured yellowy-orange to red. The fleshy fruit contains 1 to 5 distinctively shaped brown glossy seeds with a pale grey scar along one side. The fruit is reported to be edible in some texts but as always great caution should be taken in sampling any fruit from the forest.

• 

• 

• 

Timber from this tree is suitable for general building and furniture, but it was not specifically targetted by loggers.

Text and photos (unless indicated) by Jamie Oliver

Although it is neither common nor prominent among the trees along the H-track, the yellowheart (Fagraea fagraeacea) is both unmistakeble and unforgettable once it starts dropping its ripe fruit.

The yellowheart grows as a shrub to small tree (5-20m) and is endemic to higher altitude (300-1250m) rainforests in NE Queensland. As a tree it has flakey to fibrous bark with a yellowish inner bark when exposed by a blaze.

• 

• 

The leaves are elliptical to ovate and 5-10cm long. The flowers are cream coloured and can be highly perfumed.

• 

• 

• 

The genus Fagraea includes about 60 species in the Family Gentianaceae. Although there are no readily accessible (i.e. Googleable) details on any human use for this species, the yellowheart was once considered to be a part of a single, variable species (F. gracilipes) which occurs in New Guinea, the Solomon Islands and Fiji. F. gracilipes is known to produce durable, workable wood that has been used for canoes, posts and housing. The latex sap from this and several other members of the genus is used as an adhesive.

There is a solitary small tree on the H-track about 100m before the main creek crossing (walking from Lennox Cr) that, for several years, has dropped its brilliant lipstick pink fruit onto the track around August to October. It is just beginning to develop its fruit now, so be on the lookout next time you are on the Track.

Despite its striking assets (brilliantly coloured fruit and perfumed flowers and a manageable size) yellowheart is not commonly cultivated. I have twice gathered the fruit and planted them into pots to germinate so that I could add this lovely small tree to my garden but have had no success so far.

Text and photos (unless indicated) by Jamie Oliver

Yellow Pittosporum (Pittosporum revolutum) is also known as Hairy Pittosporum, Brisbane Laurel and Lemon-fruit Pittosporum, the tree is a member of the family Pittosporaceae. World-wide there are up to 200 species of Pittosporum; 16 species within Australia with six occurring in Tropical Queensland.

The name derives from pitys (pine or resin) and spora (seed), referring to the sticky seeds. Revolutum derives from revolutus, (rolled back) referring to the leaf margin.

Yellow Pittosporum usually remains a shrub, growing to around 3 metres but occasionally will grow to a small tree.  There are separate male and female plants. Yellow Pittosporum occurs naturally from Queensland to Victoria in rainforests as well as in wet sclerophyll country at altitudes up to 1100 metres.  It is an attractive shrub, eye-catching when bearing its bright orange or yellow fruit. 

Yellow Pittosporum leaves are simple, alternate or opposite; they have wavy edges and are clustered towards the ends of branches, making them appear whorled.  Leaf size can be 50 -220 mm x 15 – 70 mm.  The upper side is slightly hairy but the underside is covered with dense, rusty hairs.  Small scale-leaves are usually present.  Lateral veins on the leaf curve well inside the lateral margin, forming distinct loops.  Small white or brown lenticels (small raised, corky areas) are usually visible on the twigs.

Fragrant, yellow flowers are carried on axillary or terminal umbels or racemes during August to October.  They are partly tubular, opening to five petals.   The calyx can be green, yellow, red, purple or brown.

The yellow to orange fruit capsules appear from April to July.  The capsules are warty or lumpy surfaced, about 12-25 mm x 11-21 mm in size and may be two or three valved. These carry 20 to 76 red, sticky seeds.

• 

• 

The seeds are eaten by Satin Bower-birds and Figbirds while the flowers attract bees, butterflies and other insects.   Although the seeds are bitter it is known that they were eaten by Aborigines.  Uses for the plant range from hedges and screening, erosion control (it germinates readily and is fast-growing), and for fragrant oils.

• 

• 

• 

Around Paluma, I have found the Yellow Pittosporum growing in the re-vegetation area just outside the village and among the plants along the roadsides.  Flowering could be any time now, and there may be some late fruit clinging to the branches, so keep a lookout for this attractive plant.

Text and drawings by Colwyn Campbell

The species name “glomulifer” refers to the flowers and derives from glomulus (little ball) and -fer (bearing).  Turpentines can refer to any member of the genus Syncarpia, which is a member of the Myrtaceae family

There are three Syncarpia species all of which are endemic to Australia. S. glomulifera is the most widespread as is simply referred to as Turpentine, while the other two, S. hillii (Satinay or Fraser Island Turpentine, and S. verecunda (Red Turpentine) have more limited distributions.  The habitat most commonly associated with Turpentine is a transitional forest between rainforest and wet sclerophyll forest and woodland, in altitudes between 40 to 1100 metres.  It is found from the Big Table-land near Cooktown to southern NSW.  It grows as an emergent tree among other popular timber trees such as grey ironbark, tallow-wood, brush box, grey gum, red ironbark, mountain mahogany, spotted gum and various rainforest trees.  Here, Turpentine can be seen in the vicinity of the rose gum forest west of Paluma.

Tall and straight trunked, Turpentine is a vigorous grower and can reach a height of 25 to 60 metres in tropical areas. The trunk can attain a diameter of 1.5 metres.  Its bark is coarse, fibrous and deeply furrowed; new twigs are hairy.  It is also a long-lived tree and some specimens are said to have reached 300 years.

• 

• 

The elliptic leaves are simple, opposite or whorled. 30 – 110 x 14 – 45 mm in size.  The upper side is glabrous or minutely hairy while the under-surface is covered in white hair, with brownish oil dots visible with a lens. The leaves are mid green, red when young, with wavy margins.  They are aromatic when crushed and this aroma reminded early settlers of turpentine, hence the common name.

• 

• 

Syncarpia glomifera flowers photo by Casliber CC by SA 3.0

Syncarpia seed capsule (about the size of a marble)

Flowering occurs from August to February.  The fragrant flowers are clustered in axillary or terminal heads. The flower has four or five white or cream petals and fine filamentous white or cream stamens, similar in appearance to many Australian native flowers.  They are very popular with pollinators like European honey bees, native bees, grey flying fox, little red flying fox and birds such as lorikeets.

Fruiting occurs between November and July.  The grey or brown fruit is an aggregate capsule 10 – 12 mm long and 12 – 22 mm wide. There are usually seven valves containing numerous orange/brown seeds about 2 mm long.

Turpentine was much sought after as a hardwood with its reddish-brown colour ranging to a deep chocolate brown and its coarse even texture with a straight grain.   It is an excellent timber for dance floors.  It is also used in the construction of plywood, laminated beams, bench tops, joinery and parquetry, boat building and wine casks.  Because the timber is fire resistant and highly resistant to termites, marine invertebrates and borers, it was much in demand for piers and building foundations.  During the War years, Archie Taylor cut two turpentine logs over 100 ft long (one was 128 ft) for an American Radar station.  It took several days to get the logs down the Range to Moongoobulla.

The area around Paluma was heavily logged, especially during the War-time years. So much so, that there are not even any relict trees known on the H Track or surrounding area.  There are however, several fine living specimens in the vicinity of Hussey Road and around the Blackfriars district.  Around Taravale there are many young trees.

Although the IUCN Red List status of this species is the lowest category (Least Concern), in NSW, the Turpentine-Ironbark forest of the Sydney Basin Bioregion is now listed as endangered or critically endangered in the Threatened Special Species Conservation Act, NSW, 1995 as are all the communities with which the Turpentine-Ironbark forest vegetation intergrades.   The Commonwealth also lists the Community as critically endangered under the Environmental Protection and Biodiversity Conservation Act, (Commonwealth) 1999.   The fate of these trees is an example of how easily and quickly human activity can change an environment and the habitats of many insects, birds and animals.

Turpentine trees have been introduced into Hawaii, Africa, New Zealand, and the Cook Islands and the species is considered an invasive weed in most of these areas.

For detailed information on the timber industry around Paluma, I recommend Linda Venn’s book ‘Paluma: the First Eighty Years 1870’s to 1950’s.’

Next time you drive out to the rose gum forest, see if you can identify the turpentine among the gums, stringy barks she-oaks and other trees.

Text and photos (unless indicated) by Colwyn Campbell

The umbrella tree (Schefflera actinophylla) is native to tropical rainforests in Queensland and the Northern Territory as well as New Guinea and Java. It is an attractive fast-growing evergreen tree that colonises disturbed areas. As a young plant, it can be hemi-epiphytic or lithophytic, growing on and up boulders and the trunks of larger trees. The large elongate leaves are palmately compound, arranged in a circular “umbrella”.

Deep red flowers are borne on long terminal spikes and are copious nectar producers that attract a variety of insects, birds and small mammals. The nectar and fruit can sometimes ferment resulting in mildly intoxicated, rowdy parrots that may occasionally fall out of the tree, too drunk to fly. The leaves are a favourite food of Bennets Tree Kangaroo

The umbrella tree is a popular house and garden plant in Australia and around the world. It has also been used to create bonsai trees.

Umbrella trees are quite common in gardens around Paluma village and occur occasionally in the forest behind backyards. Naturally occurring trees can most easily be found along the range road and along the creek upstream from the Little Crystal Creek Bridge.

Schefflera actinophylla has become naturalised in many countries. In southern Queensland and parts of NSW (outside its native range) it has been declared an invasive plant invading national parks, remnant bushland, undisturbed forests and reserves.

A related species, the dwarf umbrella tree (Schefflera arboricola) is also a popular decorative plant in Australia, with at least one specimen prominently growing on the corner of Whalley Cr and Mt Spec Road. It is a native of Taiwan and eastern Asia but is considered is a minor or potential environmental weed in Queensland and north-eastern New South Wales.

Text and photos (unless indicated) by Jamie Oliver