Andrew’s Blog

Flora of the Hunter Region Book review

I was pleased to attend the book launch and museum exhibition of this stunning new book, the event held at the Newcastle Museum

This is a remarkable publication, given that it provides detailed and authoritative botanical monographs of 54 trees and shrubs that are endemic to the Hunter region, each one of which is accompanied by a full page scientific illustration.

The lead author, Dr. Stephen Bell, is probably the leading botanist in our region, having undertaken countless plant surveys over the last 25 years.

The fact that the other two co-authors, Christine Rockley and Dr. Anne Llewellyn, are both scientific illustrators, demonstrates the significance placed on the illustration component of this book. In fact as many as 20 different illustrators were used, all alumni of the Bachelor of Natural History programme at the University of Newcastle.

Andrew with illustrator Candice Rogers at the book launch

I was lucky enough to be photographed with the illustrator of Eucalyptus aenea, Candice Rogers.

One of the features of the launch was the stunning display of framed, enlarged prints of all the book’s illustrations, along with a video describing the process involved in the field surveying, collecting, cataloging, creating herbarium specimens, describing and illustrating each of the 54 species.

Each monograph contains the full nomenclature and etymology (origin of the botanical name), distribution (with map) and known reservation plus location of the “type” specimen, habitat including a long list of species it occurs with, flowering period, affinities with similar species and hints on differentiating them, key diagnostic features, conservation status, plus a protologue ie the original material associated with a newly published name, comprising detailed botanical descriptions.

There are numerous entries for species of interest from the point of view of their essential oil potential, but given that many of them are threatened or of limited distribution, they aren’t readily available for distillation. One such species is Prostanthera cineolifera, so named by Baker and Smith (pioneers of essential oil analysis of Australian plants) because it contains 1,8-cineole, giving off a eucalyptus-like fragrance. This species grows in a limited range centred around the Brokenback Range.

Additional information provided includes a glossary, an ecological and taxonomic bibliography, specimen collection locations plus coordinates (lat/long) for locations mentioned  and conservation assessments for each species.

The full title is Flora of the Hunter Region. Endemic Trees and Larger Shrubs, published by CSIRO Clayton Vic, 2019. A second volume is in preparation, this will include herbs, grasses, orchids and other smaller plants. The recommended retail is Au$80.00 which is what I paid at the launch, however it can be purchased online for under $60.00.

This book is a must for native plant enthusiasts in the Hunter region, and for people anywhere who enjoy botanical artistry.

Polblue, a fragile wilderness

As a way of escaping extreme heat, as well as to participate in a plant collecting trip for the Hunter Region Botanic Gardens, we headed up to Barrington Tops National Park on Sunday, observing the change in temp from 35C in the valley to 26C an hour later, at an elevation above 1400m. The plan was to camp the night at Polblue camping area, then meet our collecting colleagues there in the morning.

Along with the camping and picnic area, Polblue has a significant peat bog, surrounded by sub-alpine flora. 

Peat bog Poleblue

Peat bog with pools of crystal clear water

This area is not only of great ecological significance, it also harbours a number of rare and threatened species, including two species of mountain pepper, Tasmannia purpurescens and T. glaucifolia (fragrant pepperbush).

Tasmannia glaucifolia

Around the campsite we found an abundance of flowering veined doubletail orchids (Diuris venosa), another threatened species.

Diuris venosa veined doubletail 

There is a good walking track around the peat bog, however it is a surprise to find large piles of horse manure along the track. I took a short stroll into the peat bog and found plenty of large hoove prints deeply embedded in the soft ground. Our guide Bill Dowling indicated there are around 100 feral horses in the area, certainly one of the threats to this world heritage wilderness site.

As we progressed slowly along the track at botanist speed, another major threat is ever-present, the introduced Scotch broom (Cytisus scoparius), a declared noxious weed. While it is a reasonably attractive plant with its’ buttercup yellow pea flowers and bright green pods, this species looms as the greatest threat to the stability of this fragile wilderness.

Cytisus scoparius – Scotch broom
sparteine – a quinolizidine alkaloid

Herbalists are quite aware of this species, since it contains the alkaloid sparteine, whose actions include anti-arrhythmic (similar to quinidine, a plant-based drug used to treat arrhythmia) and oxytocic (strengthens uterine contractions), rendering it as a potential abortifacient. Historically it has been used as a diuretic. Due to toxicological concerns, use of the plant as herbal medicine has been restricted. 

Efforts to control the spread of this weed have met will little success. There is plenty of evidence of herbicide applications in the past, and while glyphosate does kill the plant, it can’t control the germination of seedlings from the rich seed bank in the soil.

Poisoned and healthy Scotch broom, plus pig disturbance

After a lunch break we drove a little way north to another section of Polblue creek, known habitat for the rare silver tea tree (Leptospermum argenteum) and two threatened species of plantain (Plantago spp.) We disturbed a wild pig, another environmental threat to the region (see photo above), and did find some silver tea tree on the creek bank although it was visibly in the process of being squeezed out by the broom. A few specimens of Tasmannia glaucifera on the edge of the creek were also being overwhelmed by the broom.

T. glaucifera overwhelmed by Scotch broom 

The continuing spread of this invasive weed is a massive problem. At Polblue hundreds of seedlings can be seen emerging in places both inside and outside of the walking trail, making a mockery of attempts at controlling this species with herbicide. In fact, I learned that the spray program was put on hold after it was discovered that around 100 T. glaucifera specimens were accidentally poisoned. 

I do have major concerns about the use of herbicide on such a large scale, as we know that much of the residue will end up in the waterways, and ultimately the Hunter River. However there is no viable alternative in sight, physical control by digging out the plants could work in theory, but the scale of the problem means we would require thousands of workers for an extended period, an idea that is clearly impracticable.

As we headed back down into the valley and the heat I had very mixed feelings. On the one hand, it is a beautiful area with so much more to explore and a selection of rare and interesting plant species. On the other hand I felt a sense of despair – it is hard to imagine that within the foreseeable future the peat bog won’t be overrun with Scotch broom, just as the nearby creeks and woodlands are already. 

From left. Bill Dowling, me crouching in background, Tim Parsons and Pat Shearston taking GPS readings.


Time for turmeric

November the time for turmeric? It is the time turmeric emerges from a long dormancy, it skips most of spring, and waits for the real heat to arrive – it is a tropical plant after all. In fact, almost 1/2 way through November and I only have one turmeric plant sprouting, I’m expecting many to emerge in coming days.

Last Autumn I dug them all up – see photo below. Sliced and dried they are being used for their culinary and medicinal qualities, while numerous rhizomes were put back for this summer’s crop.

Turmeric harvest

Meanwhile, I was fortunate to obtain some rhizomes of our native turmeric at one of our plant society meetings. Curcuma australasica is commonly known as the Cape York Lily, though it is no lily. The native species can be used in a similar way to the Asian species (Curcuma longa), the main difference being in the flowers, which appear when the plant first emerges from the soil, in my case in early November.

Curcuma australasica

Curcuma australasica. Native turmeric aka Cape York Lily.

Note that the pink “flowers”are actually bracts, concealing the much smaller true flowers. This plant can be easily cultivated, and it is available through several Queensland nurseries. It dodges winter by dying back, therefore it can survive non-tropical conditions. More information can be found here:

Flower harvest

I’m a bit too busy for blogging at the moment, but I thought I would share today’s flower harvest from the orchard garden on Southern Cross Farm.

Flower harvest Oct.2018

From top: Calendula, California poppy, red clover, chamomile.

These are dried for use in teas or tincturing. They look gorgeous in the garden, and retain their colour well when dried correctly.

Currently, I’m harvesting about this quantity about every second day. It looks like we are in for a hot dry spell as we move towards summer, having had some really good spring rains. Some of these flowers may be gone within a couple of weeks.

Happy gardening, and don’t overlook the flowers.


After the rain

Following an extremely dry spring and summer further compounded by regular heatwaves, the autumn finally brought some good rain to the lower Hunter, and with the ongoing warm temperatures it was like having summer all over again, but without the heatwave.

Second sunflower crop for the summer

While the crops were responding to the boost of rain, not to be forgotten are the weeds, just lying around dormant waiting for their moment. The most likely suspects, fireweed and capeweed (both daisies) however were usurped by a less likely but nonetheless quite common weed, known by many names including American wormseed and Mexican tea – the names giving some clue as to the origin.

Dysphania ambrosioides – American wormseed

This plant has a new botanical name since I last looked it up. Previously it was Chenopodium ambrosoides, sister to the common fat hen or lambs quarters, Chenopodium album and the popular health food quinoa (C. quinoa). However a quick check of the Plantnet site informs me it now has a new name, Dysphania ambrosoides, and that it is a cosmopolitan weed found throughout Eastern Australia and beyond.

While this plant isn’t particularly striking in appearance, it does have a quite distinctive smell, some may say stink! This is due to the volatile oil which is high in the monoterpene oxide ascaridole, a rare anthelmintic compound also found in the medicinal plant boldo (Peumus boldo). For over 100 years the essential oil (known then as Baltimore oil) was used as a household remedy in North America for treatment of intestinal parasites, however it became less popular due to its extreme toxicity.   According to “Ëssential Oil Safety” a safe dose for children was 1 drop per year of age, but 2-3 times that dose could be fatal. In a study by  Monzote et al. (2009), cytotoxicity via inhibition of mitochondrial respiration by three different components of the essential oil (ascaridole, carvacrol and caryophyllene oxide) was demonstrated.

So how does such a toxic substance become a food ingredient? Travel to Mexico and epozate as it is known is a much-loved culinary spice, added to beans and other dishes to assist digestion and add an aromatic flavour. The trick is to use the leaf only, not the seeds, and avoid the essential oil altogether. According to Mother Earth Living, you can add epazote to soups and stews, bean and squash dishes, corn, pork and fish, mushrooms with onions and to complement other popular spices like cilantro and chiles.

So there you have it – a weed, medicinal herb and essential oil, food and poison all in one. Do you have any weeds to match that in your garden?


Monzote, L., et al., (2009). Toxic effects of carvacrol, caryophyllene oxide, and ascaridole from essential oil of Chenopodium ambrosioides on mitochondria. Toxicol. Appl. Pharmaco. doi:10.1016/j.taap.2009.08.001
Tisserand & Balacs (1995). Essential Oil Safety. Churchill Livingstone.




Distillation days

One of the great pleasures  for me is getting together with friends and spend an afternoon distilling some freshly harvested aromatic plant species. This week I was fortunate to have two such days in a row.

Rosemary distillation

At Stephen and Julies’ home near Laguna, there is a rosemary hedge that has a strong aroma of rosemary. That may come as no surprise, however rosemary comes with different chemotypes, some of which are not conducive to cooking with and using for medicine. For example the plants I have growing at home turned out to be CT camphor, while CT verbenone is popular among aromatherapists. But for flavour and medicinal use I prefer the 1,8 cineole type, which we distilled on this occasion. I made sure that I took some stem cuttings from non-flowering stems, to propagate them later at home.

Rosemary harvest
Well-pruned rosemary

The rosemary bushes were overdue for a prune, we helped provide a good trim, there were enough leaves to fill the 40 liter distillation pot. Fortunately we got started in the morning, it turned into a hot day. The leaves are stripped off the main stems and added to the distillation pot.

Rosemary and me

The pot sits on a three ring gas burner, and the condenser is kept cool by running water from a tank connected to a pressure pump. This water wasn’t wasted, it run down via a hose to some young cypress specimens that were looking a bit dry.

After a couple of hours and a delicious mushroom quiche lunch in between, we called a stop though less than one litre distillate had been collected. However there appeared to be a decent amount of oil sitting on top, to be separated out from the hydrosol later.

Rosemary distillate
Distillate with essential oil layer

In the end we made about 20mL of essential oil, along with the hydrosol. Typically the oil has a fresh aroma featuring the high notes. It will oxidise a little and should turn into a good quality rosemary oil in a month or two.

Callistemon distillation

The following day I visited my friend Terry on his bush surrounded residence near Elderslie. I had in mind to distill the Melaleuca decora I had observed growing there, but decided there weren’t enough trees for harvesting. However nearby was a large stand of red-flowering bottlebrush, Callistemon linearis.

Image result for callistemon linearis tree

Some authorities, including the Queensland Herbarium, now place all Callistemons in the Melaleuca genus, in which case this species would be Melaleuca linearis. The NSW Herbarium has yet to adopt this switch so I’m keeping with the old familiar name – along with most native plant lovers I still refer to these as Callistemons.

It turned into another hot afternoon, and an hour or so of harvesting the rather prickly leaves left us rather thirsty. Fortunately we had a six-pack of Coopers Pale Ale on hand, which we imbibed while the still boiled away and distillate poured out copiously for a couple of hours. This turns out to be a low yielding species, and no appreciable amount of oil was separated in the aftermath. However we obtained plenty of hydrosol, which is useful for all kinds of household and cleaning uses, and Terry likes to heat it in an oil burner to keep the air pure indoors.

According to an authoritative text (Brophy, Craven & Doran, 2013), essential oil produced from this species contains over 60% cineole, along with terpenes such as pinene and limonene. Hence it is a Eucalyptus-style oil with notes of pine and lemon. Traces of these chemicals are retained in the hydrosol providing the characteristic aroma. According to the text yields are as low as 0.1% hence it is little surprise that we failed to obtain any under the circumstances. However we shared a most enjoyable afternoon, and our hydrosol stocks received a timely boost.

Brophy, Craven & Doran (2013). Melaleucas. Their Botany, Essential Oil and Uses. ACAIR, Canberra.







The summer garden

I am fortunate to have inherited a slightly run down orchard, with high fencing to keep out the kangaroos and other critters, and plenty of open space for gardens.

Sunflower and garden


Sunflowers, sage, sweet peas, comfrey and chicory along the fence line.

The beds in these photos were formed last year from composted weeds dumped along the fence line. Wait a year and you have ready made garden beds, they work especially well for pumpkins and melons. A  little added compost or organic fertilizer help to get things moving.

The citrus trees were previously being choked with perennial grasses, notably kikuyu. It took plenty of manual labour to remove a strip of grass roots from around each tree and replace with mulch. I found the trees are now quite happy to accommodate having gardens around them as the picture below reveals. In this case echinacea, yarrow and lemon balm are growing profusely, while under the bird netting is a lush crop of red clover just beginning to flower.

Echinacea and other herbs sharing space with citrus tree

The bird netting was installed to keep the wood ducks at bay, our local ducks just love to eat back the clover! If using this method ensure the trees and herbs are being provided with adequate nutrients and fertilizers. The red clover is a fertilizer in itself, it will be cut back for mulch and/or turned in as a green manure crop. I also grow buckwheat in a similar way,  and it doesn’t need protection from the ducks. It can be cut back for using as mulch, and if left to seed you can harvest them for the kitchen, or leave them to self germinate and produce another crop of mulch.

At this time of year the garden is supplying our kitchen with potatoes, carrots, zucchinis, cucumbers, tomatoes, asparagus, hot chillis, beans (5 varieties), strawberries, greens and more. In November I harvested the garlic patch, and it looks like we could have a years supply!

Garlic Nov18
Garlic “curing” in a shady spot

We’re most concious of growing food for medicine, other examples are turmeric and ginger, we also have the native turmeric (Curcuma australasica) not to overlook the native ginger (Alpinia spp.)

Baikal scullcap (Scutellaria baicalensis) and summer savoury


Then there are the strictly medicinal herbs finding spaces around the citrus trees and fenceline beds, these include Calendula, ashwaganda and baikal scullcap – all currently flowering profusely.

Other summer garden crops we are waiting to mature are corn, okra, melons, pumpkin and eggplant. We started harvesting tomatillas, they make the best green salsa and so easy to grow.

The spring lettuce have self sown, lets wait to see whether they can make it in the anticipated January heat (40C+ forcast for the weekend).

As I mentioned I am able to grow a lot of my own mulch (including grass clippings), however some animal manure is also necessary for adding to the compost. The four resident cows were just moved on to greener pastures, fortunately I can harvest their droppings for a while yet.

For anyone reading this, I wish you a happy new year, and I hope you have plenty of good produce to enjoy and share this summer.













Herb wildcrafting at Hill End.

Hill End is a semi-ghost town west of the Blue Mountains, remnants of a thriving 19th century mining settlement whose population once reached 40,000. Today the remnant buildings are preserved as a designated historic site, with many hectares of open commons and surrounded  by abandoned gold digging mounds and gullies.


My first visit to Hill End was in Nov. 1989, as part of an excursion with the National Herbalists Association of Australia (NHAA) – archivists may locate the excursion report in Australian Journal of Medical Herbalism vol.2, 1990. There is plenty of herbal history at Hill End, but even more enticing, the old diggings and neighbouring Common host a variety of naturalized and largely undisturbed European herbs, in particular hawthorn (Crataegus spp.) (in full flower back in ’89), covered in unripe “berries” during this December’s visit. More relevant to the current visit, St. Johns’s wort (Hypericum perforatum) is flowering and abundant.

Kangaroos and St. John’s wort on the Common.

Camping at the Village Campground, there was abundant wort withing a few minutes walk, along with other herbs right for the picking, such as centaury (Centaurium erythrina – see earlier blog), self heal (Prunella vulgaris) the invasive Scotch broom (Sarothamnus scoparius) and periwinkle (Vinca major).

StJwortcentaury  SelfhealStJw

Self-heal among  the St. John’s wort

PeriwinkleVinca major – a uterine astringent


As usual I had some good extra virgin olive oil with me, and made up the Hypericum oil as I harvested, with enough spare to dry at home and make up the tincture. This is one of the most rewarding of herbs, providing a rich dark red coloured oil within days, and an equally dark red within minutes of making the tincture, the ethanol being a good solvent for hypericin, the characteristic pigment responsible for the characteristic colour – and some but by no meals all – of the therapeutic activity in the herbs.

Hypericum oil
Hypericum oil and tincture macerating


Its worth spending a little time looking around the old town, some impressive buildings remain, along with occasional signs of life.


Rambling rose outside shack

Well preserved

Farwell from Hill End, well worth a visit.