Junior Synonym: Elaeocarpus grandis. From a later description of the species by Ferdinand von Mueller.
Common Name: Blue quandong, Blue fig (although not closely related to a fig) or Blue Marble tree.
Etymology: Elaeocarpus: From the Greek word ‘elaia’ meaning olive and ‘karpos’ meaning fruit. angustifolius : Latin for narrow leaf. grandis: Latin for big.
Origin: Northern Territory, Queensland, New South Wales and New Caledonia.
Description: Tall tree to 35m. It is one of the fastest growing rainforest trees particularly following major disturbance such as logging, for this reason it is key in regenerating rainforests
Foliage: Leaves are glossy dark green, alternate, oblong-elliptical, bluntly rounded at apex, 10-18cm long, margins shallowly toothed. Venation distinct, obvious domatia in vain angles. Old leaves turn bright red on the tree prior to falling.
Bark/Trunk: Buttress trunk, even on small trees. Bark is light grey, slightly wrinkled with fine fissures that run longitudinal.
Flowers: Greenish-white, bell-shaped, five petals, fringed in numerous racemes borne along branches from leaf scars. Flowering March to June.
Fruit: Drupe, bright blue, globular, 2-3cm in diameter, thin edible layer of green flesh. Seeds up to 5 encased in hard pitted stone. Ripe Spring and Summer. These are eaten whole by cassowaries, woompoo pigeon and spectacled flying foxes which pass the nut undamaged making them then in an ideal state for growing new trees. Interestingly the blue colour is formed from not from anthocyanin pigments as in other blue fruits but from physical interference of blue light. This is common in the insect and animal world but virtually unheard of in plants.
Growth Requirements: Prefers full sun position, moist soil in a sub-tropical climate. It will handle light frost.
Uses: Large tree for parks and gardens, rainforest gardens, Australia native gardens. Timber is used for cabinet making, racing sculls, oars, aircraft construction. More traditional uses were as necklaces by the Aboriginal people and as a bush tucker food. The fruit is fairly sour so it is more of a survival food than something you would make a habit of eating.
Propagation: Seeds should be sown fresh, but stones should be filed before sowing. Cuttings strike easily.
Sources of information:
- Australian Trees by Leonard Cronin.
- Own horticultural notes.
- Photography by Simon Schubert.