The beautiful blossom of the Silver Princess tree – watercolour by Frank Batini
It all started one sunny autumn day back in 2017. I was chatting with botanical supremo Alex George about the different bark types of eucalyptus trees. It is a subject which I feel sure most people find enthralling … and why not? Eucalypts of one sort or another grow all over Australia from the tropics to the deserts, from the baking ironstone hills of the Pilbara to the snowy mountains of Tasmania. Most of us interact with a eucalyptus tree every outdoor day of our lives, either admiring one in the local park, pausing in the shade of one on a summer day, or simply drawing in their fragrance – that special “eucalyptussy” smell that is the very essence of the Australian bush.
And those eucalypts have interesting bark. The variety is wonderful, but they do fall into categories, and this is one of the ways the genus is organised. One lot are the ironbarks, and then there are the stringybarks, candlebarks, box barks and scribbly barks. Some eucalypts are cleanskins and others wear stockings. Some of the so-called “red gums” have tessellated bark, rather like crocodile skin; others are spotted like a leopard.
A gimlet tree, in its autumn colours with bark of burnished bronze
Gimlet (E. salubris), by the way, is not just a champion in the world of tree bark beauty but is a chameleon. The bark changes colour with the seasons in a single year from white to olive green to bronze.
Minni-richi bark
The focus of my discussion that day with Alex, however, was the unique bark form known as “minni-richi”. This is a strange term, whose origin is disputed, but it refers to a rare type of bark with strips or stripes of different colours, usually pink and green.
Minni-richi bark on a Webster’s Mallee (E. websteriana) – our homestead at Gwambygine in the background
There are only six eucalypt species with a form of minni-richi bark (Eucalyptus caesia, E. websteriana, E. crucis, E. orbifolia, E. ewartiana and the recently discovered E. minniritchi). They are all small trees, usually mallees, and with very confined distributions; basically all occur only in Western Australia. One of them, a sub-species of E. caesia popularly known as Silver Princess, is probably our most widely-planted ornamental tree [See Footnote 1].
Apart from the distinctive bark, another characteristic of most of the minni-richi eucalypts is that they retain their blue juvenile leaves into adulthood. This makes them a striking component of the bushland in inland landscapes.
The minni-richi Southern Cross mallee (E. crucis) with its striking blue foliage, at Sanford Rocks
The use of the term “minni-richi” for the bark of these eucalypts is controversial. Many botanists and foresters consider that the term should only apply to the Acacia (wattle) species that were originally designated with this name. The minni-richi bark on Acacias is different (the bark flakes and curls, rather than forming stripes) from that on the so-called minni-richi eucalypts.
“So-called” minni-richi bark on E. caesia
“True” minni-richi bark on Red Mulga (Acacia cyperophylla)
Hold on, hold on! I hear you cry! This is not interesting! Who wants to listen to botanists barking at each-other about bark! Get onto that story about the footsteps of James Drummond in the title of the story!
Sorry. Yes I did get carried away there. Back to the story, to Drummond and to one of his most notable plant collections - the Western Australian Silver Princess tree, Eucalyptus caesia, one of the most popular ornamental trees in the land.
Some years ago, Alex George told me, he had worked in the world-renowned herbarium at Kew Gardens in England, and while there he had looked up and photographed the original specimen of Eucalyptus caesia. It had been collected by James Drummond at Mt Stirling in Western Australia in 1847.
Alex’s photograph of the original type specimen of E. caesia, collected by James Drummond in 1847 and now in the Herbarium at Kew
This observation by Alex brought together three things that made my ears flap: (a) E. caesia, a tree I love and many hundreds of which I have planted over the years; (b) James Drummond, the pioneering Western Australian botanist for whom I have always had the greatest admiration; and (c) Mt Stirling, a magnificent granite monolith in the WA wheatbelt, a place of outstanding beauty and ecological interest. What a trio!
So, right then and there, I decided: a trip to Mt Stirling was on the agenda and, if we could, we would rediscover the very spot where Drummond made his momentous discovery of this momentous tree, all those years ago.
First, a word on James Drummond
Drummond, a Scotsman, arrived in the Swan River colony (later to become the State of Western Australia) with the first fleet of settlers in 1829 and was appointed our first Government Botanist. Over the next few years, he traversed the southern half of the State, collecting botanical specimens and setting the basis for the first major classification and naming of our unique flora. It is said that he collected over 3000 plant species.
A delightful description of him was given by his biographer Rica Erickson:
Old James Drummond, with his two white packhorses and kangaroo dogs, was a familiar figure throughout the colony. Described as a plain but agreeable old man, his dour Scottish face was framed by bushy white whiskers. He usually walked everywhere, his horses being laden with stores on the way out and specimens on the way home. When his knapsack and pockets were filled with plants his white head was bared and his hat was crammed to the brim.
James Drummond photographed in 1860, with his grandson James.
Drummond was an indefatigable botanist and a tough bushman. In 1847 he planned a major exploration of the country to the east of the Swan River, and then down all the way to the south coast, a journey (all on foot) of perhaps a thousand kilometres. The first leg of this trip took him to Mt Stirling and the neighbouring granite Mt Caroline, about 150 km or so east of Perth. It was here that the collection of the specimen of Eucalyptus caesia (now in the Herbarium at Kew) was made, although Drummond did not give a precise location. This is understandable. For most of the time Drummond was botanising in the Western Australian bush, he was ahead of the surveyors and map-makers. Frequently the locations of his collections are vague; however, in this case, Mt Stirling and Mt Caroline were already known and had been named before he went there, so we can be certain that E. caesia was collected on one or the other.
Reaching the two great granites, according to Erickson:
…after making his camp by a permanent waterhole near a great rock, Drummond botanised assiduously amongst the masses of granite, in the chinks and crevices of which he found ‘quite a peculiar vegetation, and many plants he had never seen before’.
Then suddenly poor Drummond was struck with that curse of the early Australian bushmen, ophthalmia, a severe inflammation of the eyes, and he became temporarily blinded. His explorations were cut short, and he was forced to return, travelling by night as his eyes could not stand the light. His packhorse led him home.
While we don’t know whether E caesia was collected by Drummond on Mt Stirling or Mt Caroline, it was probably the latter. The tree is very rare on Mt Stirling, only 20 individuals ever having been discovered there, while there are hundreds of them on Mt Caroline.
Drummond wrote a letter to The Perth Inquirer in November 1847 in which he described his trip to Mts Stirling and Caroline. He does not mention E. caesia but does comment on the abundance of rock wallabies on the granites, and of sandalwood in the adjacent bushlands.
Mt Stirling
The main Western Australian agricultural region, known as “the Wheatbelt”, is a vast region, mostly flat or gently undulating, punctuated by salt lakes and a small number of seasonally-flowing rivers or creeks. A wonderful feature of the area, however, are the scattered enormous granite domes, known as inselbergs. They rise up from the surrounding wheatlands, perhaps up to 200m in height and often a single rock covers hundreds of hectares in area. They are pocked with rock pools, patches of mallees and scrub and are even, in some cases, criss-crossed with low stone walls constructed for rainwater collection. Standing on the top of one of these giant rocks, the air is crystal clear, cool on the hottest summer day and in winter with a keen nip. You can almost see the curvature of the earth at the far horizon.
Ellen atop a wheatbelt granite on a nippy winter day, the curvature of the earth seems to be visible beyond
Mt Stirling is just such a rock, one of a pair with its near-neighbour Mt Caroline. They are located to the north of Quairading, in the country known to the indigenous people as ‘the Mullean’ – the place of a great mythological snake, the coils of which were represented by the upthrust granite domes.
Mt Stirling has two peaks, bisected by a deep gully, thick with scrub and York gum trees.
The “discovery” (in European terms) of Mt Stirling and Mt Caroline was made by the indomitable Ensign Robert Dale, WA’s first inland explorer, also “discoverer” of the Avon River and lands that later became the wheatbelt. In October 1830 he had set off from the vale of York and walked east, encountering for the first time the beautiful gimlet tree, which he called “cable or fluted gum”. His journal records:
… . at the conclusion of 15 miles, we entered a dense forest of gum trees & brushwood, which we penetrated with difficulty, after walking nearly 5 miles through it, we arrived at a tea tree & samphire swamp, the water of which was brackish; at the eastern extremity of it we reached the base of two remarkable isolated hills for which we had been steering; we found each of them to be composed of one immense mass of granite; they appeared to be detached a short distance from some high land, stretching away to the Southward. We gave the Northern one, the name of Mount Caroline, & the Southern, was called Mount Stirling, from my fellow-traveller Mr W. Stirling.
Mt Caroline to the north, taken from near one of the summits of Mt Stirling, Oct 2017
Although today it is surrounded by privately owned farmland, the rock has been reserved since 1908, and these days is a Nature Reserve. Like the other great granites of the wheatbelt, Mts Stirling and Caroline are remarkable for their diverse and unique flora [Footnote 2], and also for being one of the few areas where rock wallabies have survived (and today are starting again to prosper, thanks to fox control).
Our expedition: retracing the steps of Drummond
It was a propitious date, October 17th (my birthday), and a tip-top spring day, cloudless, warm and sunny. We were Alex, our botanist, my mate Frank Batini, always good company and handy at finding things in the bush, and me, general factotum. Unlike Drummond, we did not walk, leading a packhorse, but travelled in my Subaru Forester, the perfect bush vehicle. Also, unlike Drummond, we knew it was the right time to be looking for Eucalyptus caesia, as there seemed to be one in every second park or garden we passed as we drove out of the city, all of them a mass of pink blossom.
Alex had also been careful to pick up a permit from the department authorising him to make botanical collections in a Nature Reserve. All of the minni-richi eucalypts are classified as endangered species.
We did not know at the time that E. caesia occurs prolifically on Mt Caroline but is rare on Mt Stirling. On the other hand, both Alex and I had been to the mounts before, and we knew that Mt Stirling was easier to get to on a one-day trip up from the city. That was the good news. The bad news was that we also knew that Mt Stirling was a big rock, over 220 ha in size. The upper slopes were steep and rugged and the gulleys impenetrable with scrub and mallees.
We started on the west side near the ruins of an old bush church, climbing up steep slopes and through prickly scrub to the southern of the two peaks of the rock. Quartering the whole area, we found no E. caesia, although I did spot a euro:
We then moved around to the east side of the rock, ate our picnic lunch, and split up. Alex decided he would investigate a deep ravine, while Frank and I scrambled up the main east-facing flank of the rock. I might add that I was not travelling too well at that time, with a wonky arthritic ankle and a hip that was overdue for replacement. The rock climbing was arduous, and I found I had to traverse the slopes rather than scramble straight up. Nevertheless, in this way we managed to cover a lot of ground and got to within a hundred metres or so of the summit.
To our disappointment, we found not a single E. caesia tree. I began to flag and suggested a return to the vehicle, and the boiling of a billy. But Frank felt we should mount the final ridge before the summit, and he talked me into accompanying him.
Then came a lovely moment. “Look at that!” Frank exclaimed, and following his pointing finger, I could see a wonderful splash of pink and grey against the skyline. Sure enough we came upon four or five small clumps of multi-stemmed trees, unmistakably E. caesia – all a mass of pink blossom. They grew seemingly from the very rock itself:
We spent a happy half-hour scrambling around, taking photographs and collecting two or three specimens to take back for Alex in case he had not been as lucky as us. All of the trees were covered with blossom, and of course had the expected, striking minni-richi bark.
Massed blossom on one of our discovered trees
.... and its "mini-richie" bark
Eventually we made it back to the vehicle for a billy of tea and rendezvous with Alex, who had found a great many interesting plants, but no E. caesia. He took charge of the specimens and made sure they were properly pressed and labelled.
A pair of bedraggled old bushies: botanist Alex and forester Roger, plus the specimens of E. caesia collected by Frank and Roger.
I was especially pleased to hear later that Alex had lodged both specimens, one with the WA Herbarium and the other with the herbarium at Kew in London, where it would eventually end up filed with the original specimen, collected by James Drummond, 170 years previously.
What had we achieved? As far as botanical science is concerned, not much. But on the other hand, there was a palpable feeling of satisfaction in the car on the way home. We had rediscovered a rare tree in a far-off place, maybe something not too many people had done with that particular tree in that particular spot over the years. We had retraced the footsteps of one of Western Australia’s botanical icons.
And besides, as the old forester’s saying goes: “a day in the bush is as good as a holiday”. Once again we had reinforced this Great Truth.
Footnotes
1. I have a special regard for the Silver Princess (E. caesia), as it was first identified in the bush by my hero, the pioneering Western Australian forester George Brockway. If anyone is interested, I have published a brief biography of Brockway, entitled The Forgotten Conservationist.
2. Nothing to do with Eucalyptus caesia, but I will leave you with a final and beautiful image. This is the flower of Grevillea magnifica subsp magnifica, one of several plant species found only at and near Mt Stirling, photographed by Steve “Guru of the Granites” Hopper:
References
Dale, Robert (1833): Second Journal of an Expedition whilst Exploring the country eastward of Darlings Range. In Western Australian Exploration, Volume 1. Hesperian Press, Western Australia
Drummond, James (1847): Letter to the Editor of the Perth Inquirer, November 3d, 1847
Erickson, Rica (1969): The Drummonds of Hawthornden. Lamb Patterson, Osborne Park, Western Australia
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