|
Coast Canthium is an understory tree found mostly on the fringes of tropical rainforest,
and in adjacent tall open eucalypt forest, where it has access to more sunlight. When in
dense shade it becomes a tall spindly tree, but given some sunlight it develops long,
arching branches that seek out the light. The species is part of the family called Rubiacae, which includes the Coffee Bush (Coffea arabica) that has become naturalised in Australia. Another member of the family is Morinda citrifolia which produces the Noni Fruit, much acclaimed in health food circles. |
The leaves are arranged in pairs along the branches, forming two ranks, and flowers form in the leaf axils, in groups of up to eight.
The new leaves are bright green and soft, and are often attacked by leaf miners, causing the leaves to curl.
As the leaves age, they become darker and leathery, and various moulds and lichens take hold. Note the pointed feature on the twig between the leaf pairs - this is called a stipule, and probably is a rudimentary protection for the growing tip.
There is another world going on at the microscopic level that we rarely see.
 |
On the underside of the leaf, between the main vein and some of the side veins, there
are tiny features called domatia - a swelling forming an enclosed cup, or foveole. These act as refuges for mites from their predators, and in return the mites provides some protection from fungal attacks on the damaged leaves. 
|
and a shiny black ant (unknown),
and this wary little jumping spider (unknown) that patrols the branches.
The leaves seem to be a favourite sunning spots for butterflies - this one is a Common Eggfly male (Hypolimnas bolina).
This is a Blue Tiger (Danaus hamatus).
And this is a Northern Ringlet (Hypocysta irius).
And a Small Green-banded Blue (Danis danis) - the green band looks blue to me:
This fly is a bluebottle (Musca sp.). They often spend time on the undersides of the leaves too :
The Leaf-curling Spider (Phonognatha sp.) builds a horizontal web, supported by numerous strands running up to twigs. When it catches a leaf (here from Pink Bloodwood) it sews the leaf into a tube to form a lair. It is then able to survive almost out in the open, and hunt for small prey, like this ant.
The tree also provides shade and cover for ground-dwelling species - this Agile Wallaby (Macropus agilis) is a shy and skitish creature, whose response to every disturbance is to hop at full speed through the undergrowth.
The flowers have 5 petals, partly fused to form a corolla tube. The petal tips and the throat of the tube carry erect hairs. They start off white and become yellow as they age. They have a faint, creamy scent.
When the tree is in flower, butterflies are attracted to the nectar, and do the job of pollenation for the flower. This is a Black and White Aeroplane (Neptis praslini)
(note the Assassin Bug sizing up his prey - this one is probably too big for him).
This is a Helena Brown (Tisiphone helena)
And this is an Australian Rustic (Cupha prosope)
This looks like a kind of wasp.
Bees like nectar too, of course : Honeybee (Apis mellifera), Native Honeybee (Trigona sp.):
and Blue-banded Bee (Amegilla sp.)
When the flower's petals fall away, the fertilised ovaries remain and begin to develop into fruits.
One insect interested in the immature fruits is the shiny black ant we saw earlier. They move around the fruits tickling the tip of the fruit, which perhaps makes it ooze a tiny drop of sugary liquid.
The problems for the tree are not over yet, because whenever there is a source of food, like the rich sap that provides the energy for fruit growth, you can be sure that something is going to want to take it. Many of the immature fruits get stung by fruit flies and moths, and before the fruit have fully developed, the eggs swell up and burst through the skin.
It might look like those bright spots are little worms, but that is a trick of the light. What you see is actually a mass of growing eggs, held together by a very sticky, clear goo. When these are teased out, you can see them better.
And when they hatch you get one of these - a moth larva, which is about 4 mm long and has long spines along its body:
Many of the fruits never make it to maturity, but they have played their part in keeping the moth's life cycle going.
The fruit has quite a bit of flesh on it, for a rainforest fruit, with two hard seeds inside, shaped like bananas.
The fruits are a great favourite of birds. As they hop from branch to branch, the branches swing and sway quite violently, which attracts the attention of the alert photgrapher.
This is a male Figbird, the northern "yellow" variety (Sphecotheres viridis var. flaviventris) :
and here is the female :
This is a Yellow-spotted Honeyeater (Meliphaga notata) :
This is a Torresian Imperial Pigeon (Ducula bicolor) :
This is a Metallic Starling (Aplonis metallica) :
and this time it has brought its young one along:
This is a Spotted Catbird (Ailuroedus melanotis) :
Sometimes a queue forms, with the more cautious birds waiting for their turn, watching intently from a nearby branch. This is a Yellow Oriole (Oriolus flavocinctus) :
Time to move in:
|
The birds eat the fruit and fly off, and eventually pass the seeds out to fall well
away from the parent tree. The seeds germinate quickly, and aided by the small drop
of fertiliser, provided courtesy of the bird, begin the cycle again. As I hope you can see, this tree plays its part in the web of life in the tropical forest - being eaten by insects, absorbed by fungi, providing a place in the sun for lichens and butterflies, providing shelter to protective mites, and foraging space for ants, assassin bugs and spiders, while feeding butterflies, bees and birds. If you have a frost-free garden, this would make a wonderful native addition. |
These photos and many more are also available through Dave Kimble's Rainforest Photo Catalog