Friday, October 29, 2010


Something we grow here and is a very important foodstuff, in lots of places, is banana. It was a considerable interest to me to learn that PNG was the probably the original home of this food crop.  There is evidence from the Western Highlands of human cultivation of this plant from at least 7,000 years ago:

It seems as if , maybe by chance , a hybrid occurred between 2 inedible Musa species , creating a plant with an edible fruit and this was spread by humans to South East Asia/India/China. Bananas are recorded in Buddhist texts from 600BC. Alexander the Great is attributed to having taken them to the Middle East and  thus the Romans were familiar with them.  Musa - the genus name -  was a Roman physician who recommended this food to Augustus Caesar.  In about 650AD, Arab traders took plants to Madagascar and Africa. From there, Portugese and Spanish sailors took plants to the Caribbean and the Americas in the 1500's.  What an amazing historical journey for this plant.  Whilst in PNG  I would have liked to have seen wild banana plants but unfortunately this did not happen.

There is a very comprehensive Wiki on banana :

Egum atoll - "sugar" banana bunch 

There was several varieties of bananas on sale in the markets we visited including plantains (cooking bananas) , small sugar bananas  and a larger variety  (not sure the name). There was also a dramatic purple/red variety.

Pubmed search - not much, surprisingly. There was a couple of abstracts basically showing that green (cooking) bananas have resistant starch that acts like dietary fibre. Dietary fibre is useful in diabetic treatment - it improves control and one study ( abstract 28) did show over 4 weeks that diabetic patients given "native banana starch" had weight loss and reduced insulin production.

Here's a bunch of a variety called  "lady finger" . There is a limited number of varieties back yard gardeners are allowed to grow in Queensland  because of certain diseases.  I have harvested it now to beat the flying foxes and possums - it will ripen over the next few days/week:

Whilst  cutting the banana bunch  - a process that involves cutting the whole banana "tree" down , I noticed this kingfisher sitting on the clothes line. It is called a  Forest Kingfisher. The colour of this little bird is stunning. It does seem to be a seasonal bird and one web site I found mentioned the possibility of a migratory movement from PNG to SE Queensland:

No posts for a few days - Anne and I are off to see  Lake Eyre whilst it has water!


Thursday, October 28, 2010

Blue Quandong

The Blue Quandong is dropping heaps of brillantly coloured seeds at present. This tree we planted many years ago and it is now probably over 20m high with well formed buttresses. They are reported to grow to over 35m

Binomial name : Eleocarpus grandis
Common  name : Blue Quandong

The blue fruits are about 2-3cm diameter  and the thin layer of flesh just under the skin has a tart flavour.  They make an eye catching sight when scattered across the ground near our Chook run. We don't utilise the fruit at all but no doubt some birds and marsupials do so in the rainforest which is where this tree mainly exists.  I have never found any seedlings from this tree so this year  I think I will try and get some seed to germinate.

Also photo of the progress on the water chute- the bottom pond
is largely complete apart from water plants and setting up
the solar pump ( still to be got). Construction was old railway sleepers with a rubberised pond liner.

Also photo of the rose arch - Lamarque and Pinkie are the varieties.

Tuesday, October 26, 2010

PNG trip

Apart from some work on the water sluice/pond I'm not up to much in the garden yet.

Here's some PNG photos :

Alotou (Milne Bay) Tree panadanus

Panapompom- copra drying shed

Panapompom -vegetable garden

Panapompom was our first village visited - it is in the Louisiade archipelago.
The vegetable gardens are moved regularly as the soil is quickly depleted of nutrients with the heavy tropical rains. Note the fence to keep wild pigs out.

Egum Atoll -  traditional village - children waiting for empty water bottle  

This village was set on the edge of a white sandy beach - talk about idyllic.
Our cruise ship was only the third to call in 10 years and some of the children had never seen white people. The children sang for us in the school (the PNG national anthem) and bought a tear to most of us -it was so beautifully sung.


Monday, October 25, 2010

Betel Nut

Betel Nut

One stand out item on our trip was the usage of Betel nut by lots of Papuans including some quite young ones. It seemed to be a very important cultural and economic item - Betel nuts , and the associated packets of lime and bean type pod called Daka were to be found every place in usage and for sale. Betel nut palms where also very common in and around the villages we visited.

Binomial name : Areca catchu

Common name : Betel nut

It is a tall slender plant up to about 30m- a bit like a Bangalow palm and bears clusters of seeds ( actually a drupe) that are green when unripe and yellow when ripe. The seed has an outer covering (husk) and a soft inner part when freshly cut or broken open. This is the part that is chewed.

The picture above shows the amazing climbing skills of the natives-  using a small loop of rope around the tree and his feet this man scaled the tree as if he was walking on flat ground.
There is a very long history of usage of this plant by humans in such places as India , Sri Lanka and the Pacific Islands such as PNG. The Aborigines did not seem to use it. About 10-20% of the world's population use it as a mild stimulant – it is the 4th most widely used psychoactive substance after nicotine, alcohol and caffeine.

In the parts of PNG we visited, a portion of the nut was first chewed and then a bean like plant pod called Daka was dipped in lime and a part of this was bitten off and chewed along with the Betel Nut.

Apparently the lime reacts with components of the Betel nut to create the psychoactive effect. The above picture is of a whole Betel nut, some lime, some broken bits of the daka and also pieces of Betel nut.

In other parts of PNG ( I think I saw some of this in the Rabaul market) the leaf is also used to wrap a part of the seed and both are then chewed. The most obvious visible effect of chewing Betel Nut is dramatically red lips and gums!

Clinical effects : the active drugs (mainly arecoline) have a quick onset and the effect seems to last for a couple of hours. These effects are mild euphoria and a sense of well being with increased arousal and alertness.
There is associated increased heart rate and even palpitations, elevated blood pressure and sweating and flushing. It is reported to decrease hunger and nausea and also diarrhoea.

Long term usage can cause a tremor and a psychosis and usage is associated with an increase risk of oropharyngeal cancers. There is some pretty dramatic effects with red lips and gums and most seemed to have pretty terrible gingival and dental disease.

There is lots I don't know about this topic. Anne and I tried a very small piece - apart from tasting fairly bitter it had no noticeable effect on either of us.

Some Pubmed abstracts:

search term : areca nut

abstract 17 Arecoline causes brain cell death by oxidative stress
abstract 41 Arecoline cause an increase in triglycerides and insulin resistance - ie leads to diabetes

search term : betel nut (there was a large number of abstracts for this search term -1400!)

abstract 10 Areca nut reduces the activity of a gene calles Ches1. This gene suppresses cell growth. This would partly explain the increase in mouth and throat cancers in betel nut users
abstract 19 Chewing Betel nut habitually was found to be diabetogenic (Taiwanese study)

search term : Areca nut drug dependency

abstract 16: 40% of betel nut users and 80% of betel nut + nicotine users can be classified as having a substance dependency. They would suffer withdrawal symptoms and would exhibit drug seeking behaviours.

Conclusion : an interesting social and cultural plant/drug that I was largely unaware of. It has some dramatic effects on the appearance of persons using it. Whilst I don't have a great depth of understanding of it, I suspect it is akin to nicotine but maybe less addictive. One wonders what our society would do if the use of this started to become popular -ban it outright or tolerate it and treat it as a health issue. Hopefully the latter.

Regarding Betel nut and diabetes - I found some old figures of prevalence of about 9% type 2 diabetes in a rural village (and another 5.7% with pre-diabetes) in PNG. Australia has a prevalence of  nearly 14% ( actual and impaired glucose tolerance)  I bet a large number of cases of diabetes in PNG remain undiagnosed and untreated with consequently reduced life expectancy. In PNG villages, diabetes could thus indeed be caused by Betel nut as the Australian causes would not apply ( high fat/carb diet , lack of exercise, obesity etc)


Sunday, October 24, 2010

PNG trip

Back from our trip to PNG -  we were on a small cruise ship  that went to some out of the way places such as Alotou ( Milne Bay) , the Bismark archipelago , the Duke of York Islands  and ended up at Rabaul. What an  amazing place to visit-  people living in a traditional subsistence way  without any access to electricity, shops, cars,  let alone such things as tv or the internet. The welcome was amazing - some places had only had been visited by 3 cruise ships in 10 years and there were young children who had never seen Europeans. The diving on the coral reefs was generally good as were the WW2 wrecks that we got to see whilst snorkeling. Of interest to me was what foods they were mainly eating. Apart from lots of coconut, there was taro, cassava, yams, bananas and different types of green leafy vegetables. Protein was from fish or chickens. There were no overweight Papuans where we visited. More later and some photos.

Sunday, October 10, 2010

Silverbeet and Rhubarb

More rain -  42mm overnight and more today. The ground is spongy underfoot and it would be nice to have a break from it.

A row of about 6 silverbeet plants (fordhook giant) is looking quite mangy

I think it has a fungal disease called cercospora  but there is also some small snails on the underside as well. Nearby a row of beetroot is also looking dire.  This is where I find lack of knowledge frustrating -  there are probably gardeners out there who would look and say - Boron deficiency or Magnesium deficiency or something similar but I am not at that level. Next garden club meeting will have to do -there is usually someone with an answer.

Also the rhubarb is growing like crazy.

The largest leaf was 650mmx 500mm and the stalks are nearly 30mm diameter.  I nearly gave up trying to grow rhubarb last year but this sole plant survived summer and has actually provided us with some stems.

No postings for 2 weeks whilst I attend a conference.


Saturday, October 9, 2010


The Feijoa plants are starting to flower and it looks like there is going to be lots of flowers and thus hopefully a good crop of fruit this year after a very light harvest last year.  This is another of the fruits we ate in New Zealand as children.

Binomial name : Acca (Feijoa) sellowiana
Common name : Feijoa  or Pineapple guava

The tree originates from Southern Brazil and for once did not seem to have been an Incan food item ,as far as I can determine. It is a slow growing evergreen tree (about 4m x 4m) with thick waxy leaves a bit like an olive tree. It has spectacular flowers:

Pollination is by bees so hopefully my native bees that are nearby find it a useful food source. The fruit is about 100mm long and egg shaped although some varieties are pear shaped. The colour of the fruit does not change when it is ripe - it stays a dull grayish green colour for most of the varieties. We normally wait for the fruit to fall as a sign it is ready, but a gentle squeeze -if soft- indicates that it is well ripened. The flavour of this fruit is superb. It has a whitish/pink granular flesh with multiple small seeds and a delicate perfume. To eat, cut in half and scoop out with a teaspoon.

Growing it in Brisbane is pretty easy but for the fruit fly problem. I originally got so fed up with losing all the fruit to this pest that I removed my trees but after finding the solution  ( fruit fly netting as soon as pollination has occurred) I replanted 2 trees, as we like the fruit that much. There is a blog post on my method for fruit fly netting on 12/8/10.

Nutritionally it is rich in anti-oxidants and a Pubmed search found some
really interesting research results.

Search term  : Feijoa sellowiana

abstract 1 : An acetone extract showed potent antibacterial activity against gram positive and gram negative bacteria. Significantly it showed more activity against Helicobacter pylori than metronidazole.  This bacterium is the one that causes stomach ulcers ( discovered by Australian Drs and resulted in a Nobel prize for medicine/physiology in 2005). When we diagnose this bacterium in a patient we prescribe Metronidazole as part of the treatment but here is a fruit that works better!  This abstract also demonstrated activity against some pretty nasty gram negative bacteria such as pseudomonas and proteus.  It would be interesting to see research on topical use against these bugs.

abstract 3: An aqueous (or water) methanol extract of leaves showed increased mineralisation of cultured human bone cells -  thus there is potential for treatment and prevention of osteoporosis. I can't imagine what eating the leaves would taste like though!

abstract 6 : Feijoa (acetonic extract)has an anti-inflammatory effect by inhibition of Nitric Oxide.

Conclusion :  a fruit tree that is easy to grow and has delicious fruit
as long as you can overcome the fruit fly problem.

Daleys have specimens of this tree for sale -   there are different varieties
but generally you need to plant 2 trees for cross pollination.

Also a picture of our first ripe peaches. This is a tropical variety -the size this year seems to be better -  one fruit is about 8cm diameter.

More rain-  42mm yesterday  and 10mm the day before. The ground is like a swamp at present.

Friday, October 8, 2010

Back yard dunny

One of our first garden  structures when we moved here is this :

There was no door, floor or let alone witch on top originally. It was sited in the middle of an otherwise empty paddock  that was about to be subdivided. I knocked on the door of the nearest house and enquired about it and was given permission to remove it.  Fortunately,  I knew someone with a crane truck who was able to pick it up intact and relocate it to our yard. Total cost was a carton of beer.  It has been the dog house for a number of years.  The witch came from Montville (behind the Sunshine Coast) but I think is made in Africa somewhere.  The door Anne found at the local Sunday market and seems to have come from an old house at Ipswich.  It fitted almost perfectly - but doesn't really give any  privacy!  On the southern side of this I planted a Richmond Birdwing vine some years ago.

Here's also photo of a cabbage we picked yesterday



Thursday, October 7, 2010

water chute

Instead of a waterfall we decided a water chute would be more appropriate beside the old mine site. So today  I purchased some old hardwood fascia  (200mm wide planks) and created 2 x 3m chutes from it. Then I needed to construct some frames for them to sit on down the slope to the bottom pond area. It has been an all day project and fortunately there has been no rain thus far.  The bottom pool needs emptying and fixed up prior to installing a pond liner, sand, gravel, rocks and planting. Then the path areas need crusher dust, other parts mulching, more planting and we will be about done for this area for now.

Couldn't wait to try some water
Water flow is going to be via a solar powered pump (no battery)
- this will fill the old concrete laundry tube  at the top. When the tub is full, a siphon will come into play and the water will empty down the chute back to the bottom pond. 

Crocodile under new bridge!

One day my yard will stop looking like a construction site!

Tuesday, October 5, 2010

Blue tiger butterfly

This morning there were 2 butterflies in the vegetable garden, one of which was this:

Blue Tiger butterfly

The image is a bit cloudy as it was taken through a plastic container as I wanted to release the butterfly unharmed.

The scientific name is : Tirumala hamata
common names : Blue wanderer  or Blue tiger butterfly

The wing span is about  7cm   (3")

It is similar in size and shape to the Monarch butterfly that most people recognise and indeed I thought it was this initially.  The Blue tiger is a tropical butterfly that comes south in Spring/Summer and can occur in larger numbers although we only see isolated ones on our property. Some internet sites state that Captain Cook recorded seeing masses of this butterfly in 1770 but a search of his journal entries whilst he was in Queensland waters did not locate any such mention, that I could find.  It is always good to check back when claims like this are made to verify accuracy as it is easy for mistakes to be propagated by simply being repeated.

The reported food sources of this plant are the milk weed and monkey rope vine  (Parsonsia straminea) - both of which occur on our property.

The other butterfly in the vegetable garden was the Common Crow 
( Euploea core)

More showers today


After all the rain there is some quite spectacular fungi growing in the damp mulch.  I have no idea as to the names of these apart from the first that we call a basket fungus



Monday, October 4, 2010

Eastern water dragon

Anne was helping at the Rose Society show at the Botanical Gardens yesterday.  When I picked her up  this lizard was sunning itself near the car -  it is an Eastern Water Dragon  and it was about 80cm long. It was so tame you could almost reach out and touch it.  Whilst we do not have this variety, we often see Bearded Dragons on our property, but I do not have a picture of one of these at this stage.  Another reptile we often find  is  the Blue Tongued Lizard. Also yesterday  a neighbour came over and asked me to catch a Carpet python  or Reticulated python that had been hanging around their house. It was sunning itself on a tiled roof.  Using a ladder I climbed up and grabbed it just behind the head and it was eventually put into a bag for relocation into some nearby bushland. The size was a good 3m or about 10 foot!

Eastern Water Dragon

Here is  the turmeric harvested from 1 plant that was in the vegetable garden. Two of the rhizomes will be replanted

The Plunkett Mallee ( Eucalyptus curtisii) is flowering at present and is a favourite with the Lorikeets and bees. It is not that successful here-  we have already had one tree die but the other two seem ok so far.  It likes drier conditions - our soil when it has rained a lot does  become quite sodden.

E Curtissi in flower
These trees were planted when we became Australian citizens  about 20 years ago.

Sunday, October 3, 2010

Pararistolochia praevenosa

Yesterday  morning we went to Indigiscapes to purchase some more native plants (mainly shrubs) for the front  eastern area of the property. Once a month Indigiscapes  (at Capalaba) has a small nursery open which sells a good range of local native plants  (tube stock) for the very reasonable price of $2.10 each.

One of the plants we collected is called:

Pararistolochia praevenosa
 or Richmond Birdwing vine.

I have already planted two specimens of this plants, one on the old backyard dunny, and another on a fence.  Both are a bit slow growing but the idea is that if enough people plant this vine, it will encourage this spectacular butterfly to return in the numbers it used to be in the Brisbane area. There are reports of "clouds" of this butterfly in earlier times. There is a Richmond Birdwing Butterfly recovery organisation which has an informative website:

Here is a google image of this butterfly :

One day I hope I get to see one or more of them hanging around our property.

Further to my efforts against Asparagus aethiopicus (asparagus fern)
I  found on the Queensland DPI site that diesel is effective against this plant when applied to the crown to the point of runoff ( ie  a good soaking). Diesel is quickly broken down in the soil and is relatively non toxic to animals so I have tried some diesel on a few clumps of this weed as well.  The  clumps are labelled and dated so I can check back later on outcome.

The hippeastrums are flowering profusely -  here is a white one

More rain yesterday -6mm in rain gauge yesterday morning and more rain since then as well.

Saturday, October 2, 2010


At the last Tamborine Sustainable Gardeners meeting the guest speaker, amongst other herbs, spoke about the benefits of having Turmeric in our diet. I have been aware of the benefits of this herb for some time and we have it growing in the vegetable garden and one of the aquaponics grow beds. These rhizomes were originally obtained through the garden club.

Binomial name: Curcuma longa

Common name : Turmeric (incorrect spelling is Tumeric)

It is native to tropical South Asia and needs temperatures of 20-30*C to thrive and dies back in winter here. Although it does not like waterlogging, it seems be growing ok in the gravel grow bed of one of my aquaponics systems. It is such a well known cooking herb that I will omit any further details and focus on the multitude of medical and scientific information available about it.

The compound of interest in Turmeric is called Curcumin.

Here are some results from Pubmed. There is a large number of studies on this plant available also in Scirus

search term : turmeric joint pain

abstract 1: A 2009 randomised controlled study ( this is a good level study) of 107 patients with primary osteoarthritis of the knee with a pain scale of  5 or more out of 10. It was compared with Ibuprofen ( = Nurofen, Brufen, Advil). Over a period of 6 weeks both groups improved as measured by pain scale, time to walk 100m and time to walk up and down a flight of stairs. The conclusion was that Turmeric ( amount was 2gm) was as effective as Ibuprofen.

search term : turmeric osteoarthritis

abstract 2: This one is a bit more technical but illustrates how our food can fundamentally interact with our cells at the level of the genes. This study found that Curcumin and resveratrol ( found in eg red wine, tea) suppresses inflammation in cartilage cells by targeting the NF-kappaB regulated gene products.

abstract 13: Human cartilage cells were treated with inflammatory agents for 3 days. Those treated also with curcumin showed down regulation of NF-kappaB and thus down regulation of 2 inflammatory pathways ( COX2 - blocked medically by celebrex and mobic, and MMP3 - blocked medically by tetracyclines)

search term : turmeric cancer

abstract 1: Curcumin induced human lung cancer cell apoptosis ( death) by down regulation of micro RNA ( micro RNA are growth regulators in our cells)

abstract 6: Curcumin significantly inhibited migration and invasion in vitro (test-tube) and in vivo (live) in head and neck squamous cell cancers.

abstract 8 : A mouse experiment of 2 groups given a diet that induced an inflammatory bowel condition and eventually bowel cancer. The mice also given Turmeric had statistically less colitis ( bowel inflammation) , no macroscopic tumours and only minor precancerous lesions.

Following up on these abstracts I checked up on the incidence of Cancer in the Indian population

(ref: Cancer Incidence rate among South Asians in four Geographic regions : Rastogi,T Devesa, S et al : International Journal of Epidemiology vol:37 no:1 pp 147-160)

The rate in India was the lowest at 111 (males) 116 (females) /100,000
The rate in the US was the highest 362 (males) 296 (females)/100,000

for colon, prostate, thyroid , lung and pancreas

but: India had the highest rate for mouth, oesophagus, larynx and cervix

Generally it is considered that mouth/throat and certainly cervical cancers are viral in origin (certain strains of herpes especially). It would thus seem that Curcumin does not protect against such virally induced cancers

I also looked up the incidence of osteoarthritis in the Indian population to see if Turmeric had a noticeable population effect. Satisfactory comparable figures were a bit hard to obtain but it seems as if the prevalence of osteoarthritis in Australia is 15% and India 22-39%.

So it seems that Australians have less primary osteoarthritis than the Indian population, so maybe eating Turmeric does not have a protective effect on our joints in spite of its anti-inflammatory activity.

Overall though it really is an excellent plant to include regularly in your diet.

Friday, October 1, 2010

Hydrocotyle leucocephala

At the last garden club meeting, Robyn showed me a plant that she was told was Gotu Kola  that was quite different to the plant -Centella asiatica - that that I apply this common name to. Indeed another member of the club was also of this opinion.

Whilst the 2 plants look similar the "correct"  gotu kola is Centella asiatica
and the plant that Robin showed me  was  Hydrocotyle leucocephala. This once again illustrates the problem  using common names.   When you Google gotu kola  images, it is evident that there is at least two plants being called this name commonly.

Hydrocotyle leucocephala is also called Brazillian pennywort and is an aquatic or semi-aquatic plant with light green and thick waxy leaves. It seems to be a popular aquarium plant.  The leaves are reported to be edible with a peppery taste.  
Pubmed had only one entry for this plant. In this study the plant was found to have various chemicals that have an immunosuppresive activity against cytokines such as TNF-alpha.   This is an important part of our immune system and is crucial in infection and inflammation. However it is also involved in such diseases as Rheumatoid Arthritis  and is targeted medically with some very expensive drugs.

Centella asiatica

Hydrocotyle leucocephala

I have previously written about Centella asiatica and it's considerable potential medical activity  (July 12).
Incidentally, Robyn was the person who got me interested in edible weeds with her discussion with Anne about Gotu kola being effective for arthritis a couple of years ago.