Homalanthus populifolius Graham
What this humble looking tree lacks in flower power it sure makes up for with spectacular red foliage. Also known as Native poplar or Queensland poplar it is a member of the Euphorbiaceae or spurge family which includes the candle nut tree. Host plant to Australia’s largest moth the Hercules Moth (Coscinocera Hercules) the bleeding heart tree is found mostly on the disturbed edges of several types of rainforests in Australia. From sub-tropical rainforest on the coastal border of Victoria and New South Wales north to Coen in tropical Far North Queensland. It is also found on some Australian islands such as Lord Howe and Norfolk Island as well as in New Guinea and Indonesia.
Bleeding Heart Trees are pioneer species, short lived approximately 20 years and fast growing and are mainly found on the edges of the rainforest. They are great at repairing damaged areas of forest by shading old growth trees for their lifespans. About twenty years or so until they can handle full sunlight and race for their place in the canopy up above them.
They grow from five to about eight meters tall and have cylindrical greyish brown trunks about fifteen centimetres in diameter with fairly smooth bark. Young branches appear red or green with soft triangular heart shaped leaves that are very large on small plants from 5 to 15 cm long and 3 to 12 cm wide with smooth not toothed edges. Leaves turn a beautiful bright red colour before they fall giving the tree its common name. Leaves turn red when senescent a term for biological aging. Which is the deterioration of functional characteristics such as the cells.
Bleeding Heart tree flowers are small separate male and female flowers on long drooping racemes that appear in the warmer months between October and December two to ten centimetres long and yellowish green to red in colour. They precede dark coloured two lobed fleshy capsular fruit containing an oily yellow aril. That ripen in late summer and have explosive covers that blast the seeds from the tree. Seeds germinate quickly in favourable conditions. But can also lie dormant on the forest floor for long periods of time. Until the right conditions such as a tree falling and allowing light to reach the understory before sprouting.
Fruit from this tree is eaten by a number of bird species including the brown cuckoo dove, silvereye, bower birds, orioles and honeyeaters that eat its fruit and disperse the seeds. It is also the host tree for the Hercules Moth that has a wingspan of 27 centimetres.