While travelling over the last 6 weeks in the Kimberley region we were surprised to see the large number of Boab trees. The Australian Boab – Adansonia Gregorio – is endemic to the Kimberley region of Australia and are highly prized for their usefulness and weird shape. Commonly called the Tree of Life’ because most of its parts are useful. The leaves and shoots of young plants are edible, the moist fibrous bark can be made into rope as can the roots, the large ovoid seed pods contain a citrus flavored creamy pulp and the seeds can be dried and ground to form a cooking flour. There are only two other regions of the world where Adansonia species are found, one being  mainland Africa (2 species)  and Madagascar (with the other 6 species). They all have different characteristics but in common is how they look like amazing upside-down trees and the indigenous peoples of these lands all have interesting tales/legends of how they came to be.

The Australian Boab – Adansonia Gregorio, grows to approx 15 metres and then just gets wider. Water is retained in the wet season to last it through the long hot dry season in Australia’s north which causes the trunk to swell and gives the outer bark the appearance of elephant skin! . There is debate over the age of large specimens because they don’t lay down definable rings during their growing cycles due to very variable conditions each season but aboriginals tell us that it takes over 100 years for the tree to attain its height and start to fill out. Some of the largest trees, such as the one in Wyndham, are estimated to be 1000’s of years old!

I was so fascinated by these weird trees that I have included an excerpt from Australian Geographic for some further interesting reading:

In 1820, on first encountering a boab, explorer Phillip Parker King was struck by the “gouty habit of the stem, which was soft and spongy [and] gave it an appearance of disease”. Living for many hundreds of years, this strange tree seems touched by the bizarre. Its often grotesquely swollen, silvery trunk sprouts writhing and wasted branches that lack foliage for much of the year. These, in turn, bear large, fragrant, creamy flowers that appear at night just before the start of the wet season. Hawk moths are the flowers’ usual pollinators, but, where boabs grow near watercourses, black flying-foxes also get in on the act. A crop of pendulous ovoid fruits duly appears after flowering. Covered in velvety brown fuzz, the brittle shell of the boab fruit encases a storehouse of seeds embedded in a mealy pulp. Both the pulp and seeds were once important foods for Aboriginal people. The roots of seedlings and the tree’s young leaves are also edible, while adult tree roots can be made into string. The boab isn’t particularly fussy about the soil in which it grows; it dots sandstone hillsides and sandy plains, basalt slopes and the sharp limestone ridges that arc across the southern Kimberley. In the semi-arid western and eastern Kimberley, it stands in isolation or in small, family-like copses beside creeks and lagoons. Found from sea level to elevations of about 300m, the boab’s range extends to the Victoria and Fitzmaurice rivers in the Northern Territory, but no further east. With its unique appearance and restricted range, the boab is the botanical symbol of the Kimberley, and the Kimberley alone. The common name ‘boab’ might reasonably be assumed to be of Aboriginal origin, but it’s actually a corruption of ‘baobab’, an Arabic word of African origin that means ‘father of many seeds’.

Boabs are sometimes found in small, family-like copses. The dimpled grey bark and distended habit of the trunk give this WA tree a vaguely elephantine look – an enigmatic echo of its African connections. How did they get here? So how does a species whose only living relatives lie nearly 10,000km away on the other side of the Indian Ocean end up in an isolated corner of the Australian continent? The origin of WA’s boab is one of modern botany’s great conundrums. Professor Emeritus Jack Pettigrew (a neuroscientist at the University of Queensland) and Professor David Baum (a botanist at the University of Wisconsin-Madison, USA) have spent many years studying the boab and its relatives, but their explanations of the boab’s origins are as distant from one another as the opposite shores of a metaphorical Indian Ocean. One thing on which they agree is that the boab isn’t a Gondwanan remnant like the deciduous beech. The break-up of the supercontinent saw Australia, Africa and Madagascar detach from each other more than 120 million years ago (mya).Genetic analysis of the species on both sides of the Indian Ocean shows they’re still too closely related for the boab to have been isolated for as long as that. What the two scientists disagree on is the manner and timing of the arrival of the boab’s ancestors on Australia’s shores. David concedes there’s still much to learn about the evolutionary relationships among the baobabs and boab, but his research suggests the genus Adansonia, to which all these trees belong, split sometime between 2 and 15mya.By then, continental drift had carried Australia close to its current geographical location, which came with an extensive tropical zone suitable for baobabs. David suspects the boab and its African relatives evolved from a now-extinct common ancestor that grew somewhere in Asia, perhaps in areas long ago inundated by rising seas. Wherever they once grew, the trees’ pulpy flesh would be unlikely to yield fossils. But, David explains, the “big hope” is that fossilised seeds, seedpods or even pollen might one day be found and provide a clue to the boab’s ancestry.

Http://www.australiangeographic.com.au