November 2018


Volume 45 No 10

Calendar

Nov
Sat 24 – 2 pm to 4pm Guest Speaker Dr Michelle Leishman and Christmas Gathering at Gumnut Hall

Dec
Wed 13 Propagation at Bidjiwong Community Nursery 10am to 1 pm

Jan
Mon 8 Deadline for January Calgaroo contributions
Wed 10 Propagation at Bidjiwong Community Nursery 10am to 1 pm

Feb
Wed 13 Propagation at Bidjiwong Community Nursery 10am to 1 pm
Sat 23 2 pm to 4 pm – AGM at Gumnut Hall


Urban Greening

As our population increases & cities expand, we are surrounded by ever larger expanses of glass and concrete. How do we keep our urban areas green?

Join us at the next meeting of the Parramatta Hills APS on Saturday 24 November to hear from speaker Dr Michelle Leishman.

Dr Leishman is a plant ecologist with over 25 years research experience focused on invasive plants, vegetation responses to climate change, restoration ecology and plant conservation. She is Head of Department of Biological Sciences at Macquarie University and Co-Director of MQ Centre for Smart Green Cities.

Our next Group Meeting on 24 November is our Christmas Gathering.

Join us for Christmas Nibbles and find an early Christmas present of a native plant.

Blandfordia nobilis – Christmas Bells

Talk by Dr Andrew Bernuetz 15 September 2018

Andrew studied plant breeding, genetics and horticulture at Sydney University before starting his company Bonza Botanicals in 2005. He specialises in ornamental plant breeding and horticulture. His career has been focused on ornamental plant breeding and the associated technologies and business and implementation leading to successfully commercialised products and plant in-vitro culture.

At our meeting in September he ran us through the process necessary to produce a new cultivar for commercial sale both here and internationally, as well as some details about Plant Breeder’s Rights (PBR).

Developing new plants with certain desired features involves re- arranging, adding or deleting genes or gene combinations. Plant breeding can have a variety of purposes, including environmental adaptation, increased yield, disease resistance or beauty. For ornamentals, beauty and resilience are desirable.

The process initially involves research and collection of plant material from a variety of sources. The actual breeding system can involve some or all of mutation, hybridisation or gene manipulation. The process of testing the resulting plants can take more than 3 years at multiple sites.

Andrew showed us some examples of plants he has breed and commercialised successfully.

His Princettia ( a development from poinsettia) is the world’s 1st commercially successful hybrid Euphorbia. It looks similar to traditional poinsettia but is easier to grow, has strong stems, is heat tolerant and comes in 5 colours. The coup was succeeding in developing a white version.

Another plant he showed us was his Brachyscome series, which comes in white, dark blue, mid blue yellow and pink. It is more compact and carries it’s flowers above the leaves and so displays better than existing varieties in the market. White and pink are best sellers.

Bonza Botanicals has also delved into development of Chillis, namely the plant previously now as Burke’s Backyard Thai Chilli, which was a mix of varieties called Bantam, thimble and Orange Bantam, which were all very hot to eat.

Bonza developed three new varieties. Salsa and Seville, which are both sewed and easily digestible and Ebony Fire which is hot. These plants fruit decoratively in summer with the fruit sitting attractively above the foliage. They are easy to grow from seed.

Dreamtime is a plant developed from the Australian Strawflower Bracteantha. It has been marketed successfully internationally , particularly in Japan.

Grandessa is a new intergeneric hybrid daisy with huge flowers and bright colours. Developed from Argyranthemum d a i s i e s i t h a s i n c r e a s e d h e a t tolerance as well. Development time was particularly long for this plant.

The talk given by Dr Andrew Bernuetz was very informative and gave us an in- depth understanding of the lengthy processes involved in developing and marketing new plant varieties.


A Fern which Changed Australian History

Adapted from article by Calder Chaffey APS Far North Coast Group 2000

Over a large area of inland eastern Australia the semi-aquatic fern, Marsilea drummondii may be found. It grows in swamps and bogs, billabongs, slow-flowing streams and in areas of temporary flooding. It grows in hot and dry inland areas when rain causes temporary filling of water holes and road-side puddles.

Nardoo – Marsilea drummondii in a pond. Photo: M Fagg from ANBG APII

At first sight it may be mistaken for clover. Its common name is Nardoo, and is a fern superficially resembling clover – a four-leaf clover. Nardoo belongs to the genus Marsilea. There are six species of Marsilea occurring in Australia and about sixty world wide. Most are not rare but are often overlooked because of their resemblance to clover. M. drummondii is the most common species in eastern Australia.

The genus is named after Count Luigi Ferdinando Marsigli (1656-1730), an Italian botanist, and the specific name is for James Drummond (1784-1863), first Government Botanist of Western Australia.

A few years ago, following particularly good rain in areas of central western New South Wales, there was much flooding. On two trips to Adelaide, in November and February, I found water lying in many places beside the Barrier Highway. Marsilea was not scarce and in places could be observed in massive patches in the water even while driving past at 100 km/h. Thick patches were present in many places from 40 km past Cobar to 43 km west of Wilcannia.

Characteristics of Marsilea

These are aquatic or sub-aquatic ferns and consist of two pairs of opposite leaves forming a circular blade, each leaf widely or narrowly wedge-shaped and capable of floating on the surface of water. They may be mistaken for four-leaved clovers because of the pattern of the four leaf blades. A clue to these being ferns is seen in the unfolding of the new fronds. Careful examination shows the young leaves to be coiled and these unfurl like a typical fern crozier or fiddlehead.

On water edges the leaves often form a tangled mass and are held semi-vertically out of the water. In deep water they either float on the surface or are held erect above the surface. Leaflets are generally covered with fine hairs. These are more abundant in specimens growing out of water. The hairs resist drying in the atmosphere and probably assist flotation. Leaflets growing out of water also exhibit “sleep movement”. This interesting phenomenon is the furling of leaflets when the intensity of light becomes low. Hence they tend to “close up” in the evening and on very dull days.

Nut-like structures on stalks develop from the rhizome, which grows in the mud. These “nuts” develop from modified leaves and it is within them that spores develop. They also contain a starchy structure which, on maturity, expands by the absorption of water.

David Jones states, when describing this family, Marsileaceae and a related family, Azollaceae, “These are the only true ferns to produce separate male and female prothalli. It is this degree of specialisation that makes the genus the most advanced of living ferns”.

Prothalli are the structures which develop from fern spores and produce eggs and sperm which ultimately produce the new generation fernlings.

Marsilea mutica

In all other ferns the individual prothallus produces both eggs and sperm but here a prothallus will produce only one or the other.

Formation of these nut-like structures chiefly takes place as the ponds dry up and rarely occurs in wet conditions. Maturation is slow and takes up to three years. This mechanism ensures that the spores can resist desiccation and is particularly suitable to inland areas of the continent and in areas of uncertain rain.

Nardoo as Food

The advent of rain commences an interesting series of events. The starchy material absorbs water and swells into a gelatinous material which ultimately bursts the structure liberating the spores. This is the useful part of the sporocarp for food and the nut-like sporocarps were gathered by Aborigines for this purpose. The formation and resistance of the sporocarp to desiccation and its abundance in good years has made it a good Aboriginal food.

The sporocarps were ground to a flour-like substance and mixed with copious amounts of water to form a thin paste. This was eaten raw or cooked into thin cakes.

The sporocarps contain the enzyme thiaminase which destroys vitamin B 1 and if taken continuously results in beri-beri. The preparation with water washes away or dilutes the enzyme, minimising its effect. The sporocarps are quite small, 4-9 mm in length and about 3 mm in width so that it must take a full day to collect enough to make a meagre meal.

Thiaminase is found in a couple of other fern genera, Cheilanthes (the Resurrection Ferns) and Pteridium (the Brackens). Strangely enough it is also found in the flesh of raw carp fish. It has been found that cholinesterase levels are raised in the t i s s u e s o f p e o p l e w i t h l o w t h i a m i n e . Cholinesterase acts in the nerve synapses and the raised levels may account for the interference to the peripheral nervous system in sufferers from beri-beri.

Thiamine or, vitamin B1, is essential in the body for the metabolism of carbohydrates (sugars) and the normal function of nervous and heart tissue. But is necessary only in a very small amount. The daily requirement is 1-1.5 mg daily or about an amount the size of the head of a pin. Normally it is obtained from food being high in yeast, whole grains, nuts, legumes, potatoes, egg yoke and meat. In grains and seeds it occurs in the germ or embryonic tissue and is stable to cooking unless an alkali is added.

The addition of baking powder, which is alkaline, therefore destroys the vitamin in cakes and wholemeal bread. It is not present in polished rice or white flour. In the process of making white flour for cooking and bread the traditional method removes the wheat germ and consequently the thiamine. Wheat germ also contains a fat which is liable to rancidity and attracts weevils. Its removal therefore makes the flour last longer.

In the fermentation of alcohol from glucose yeast causes a chain reaction of many stages. In one stage vitamin B1 combines with a chemical supplied by the yeast, pyrophosphate which acts like a catalyst. This substance also occurs in the brain of humans. In vitamin B1 deficiency the lactic acid level in the brain rises and interferes with its normal function.

Lactic acid normally results from muscle activity and is eliminated in the kidney. It is the cause of pain in the legs when you run too far too fast. Too much lactic acid is then produced for the blood vessels to convey to the kidneys fast enough to maintain the normal level in the blood. Faster removal occurs after training to increase exercise tolerance such as in athletes.

Beri-beri was a common disease in the East where a large proportion of the population subsisted upon rice as the predominant food. Most of these people refused to eat any but polished rice where, unfortunately, thiamine was removed with the natural rice dust and grain germ.

Other foods containing thiamine were not eaten in large enough quantities being either unobtainable or unaffordable. Even after the cause of beri-beri was discovered, there was great resistance to eating unpolished rice.

Nardoo and the Burke and Wills Tragedy

There are many notes on the use of nardoo as food by Aborigines in the journals of the early explorers of Australia. But perhaps the most graphic and famous are those recorded by Wills towards the end of the fatal Burke and Wills Exploring Expedition of 1860.

When they had no food left they were fed nardoo by the Aborigines and collected their own to try to overcome starvation. They made use of this food but did not prepare it properly, developed beri-beri and died from the combined effects of this disease and starvation.

At Cooper Creek on June 3, 1861 Wills wrote… “The fish being disposed of, next came a supply of nardoo cake and water, until I was so full as to be unable to eat more; when Pitchery, allowing me a short time to recover myself, fetched a large bowl of the raw nardoo flour, mixed to a thin paste, a most insinuating article, and in that they appear to esteem a great delicacy “

This fish and nardoo was given to them by the Aborigines. Wills actually describes here how the Aborigines prepared the flour in a thin paste but unfortunately did not follow the recipe. The following extracts are from the journal of W.J. Wills, found after his death on Cooper Creek. The following comments from this journal graphically describe the symptoms in the final few days of a man dying from beri-beri.

On Wednesday, June 12, 1861 he wrote…. “King out collecting nardoo. Mr Bourke and I at home, pounding and cleaning. I still feel myself, if anything, weaker in the legs, although the nardoo appears to be more thoroughly digested.”

June 14. “I feel weaker than ever, and both Mr. B. and King are beginning to feel very unsteady in the legs.”

June 15. “I have determined to chew tobacco and eat less nardoo, in hopes that it may induce some change in the system. I have never yet recovered from constipation, the effect of which is exceedingly painful.”

June 20. “Finding the sun come out pretty warm towards noon, I took a spongeing all over, but it seemed to do little good beyond the cleaning effects, for my weakness is so great that I could not do it with proper expedition. I cannot understand this nardoo at all; it certainly will not agree with me in any form. We are now reduced to it alone, and we manage to get five pounds per day between us.”

June 23. “All hands at home. I am so weak as to be incapable of crawling out of the Mia Mia.”

June 28, the last entry in his journal. “Nothing now but the greatest good luck can save any of us; and as for myself, I may live four or five days if the weather continues warm. My pulse is at forty-eight, and very weak, and my legs and arms are nearly skin and bone. I can only look out, like Mr. Micawber, for something to turn up. Starvation on nardoo is by no means very unpleasant, but for the weakness one feels, and the utter inability to move oneself, for as far as the appetite is concerned, it gives me the greatest satisfaction. Certainly fat and sugar would be more to one’s taste; in fact, those seem to me to be the great stand-by for one in this extraordinary continent; not that I mean to depreciate the farinaceous food, but the want of sugar and fat in all substances obtainable here is so great that they become almost valueless to us as articles of food, without the addition of something else.”

He died within the next four days and Bourke died on June 26/7. In spite of starvation the fern was primarily the killer!

Beri-beri

Beri-beri is a disease first described by Jacobus Bintius, a doctor who graduated in 1614 and commenced practice in Leyden. He was also an ardent student of botany and natural history.

He found medical practice poorly paid and eventually joined the East India Company and migrated to Batavia in 1627 where he became Attorney General. Here, in his spare time, he observes the flora and fauna and wrote four books before he died in 1631 at the age of 39.

His books described the fauna, flora, fish and medicine in the East Indies. In Medicine Indorum we find the first description of beri-beri.

“This is a type of paralysis which the natives call beri-beri. Beri-beri means sheep……with knees shaking, and their legs raised up, (they) walk like sheep. It is a kind of paralysis, or rather Tremor for it penetrates the motion and sensation of the hands and feet indeed sometimes the whole body and produces tremors. There is a lassitude of the whole body.”

So far his observations were accurate but when he got onto the cause he went wrong – assuming rather than investigating. He stated: “The especial cause of the disease is the dense and sticky phlegmatic humor, which in the nocturnal time, particularly in the rainy season. corrupt the nerves…”. We now know that the cause is vitamin B1 deficiency. Of course vitamins were unknown until early this century. The symptoms of beri-beri are:

  • Loss of appetite, which causes the disease to progress as thiamine is absorbed from food. Pleural transduate (a serous effusion into the airways of the lung).
  • Chyne Stokes respiration or periodic breathing (breathing which gradually increases in depth and then gradually diminishes to stop for up to a coupleof minutes before recommencing the cycle again). This type of breathing can be normal in some young or old people but may denote grave disease. Here it is caused by myocardial weakness and cardiac insufficiency (weakness of the heart muscle and heart enlargement denotingcardiac decompensation or partial heart failure).
  • Generalised oedema (collection of serous fluid in the tissues) due to cardiac failure and hypoproteinaemia(low serum protein due to failing kidney function).
  • Palpitation (consciousness of the heart beat which sometimes may be fast) due to cardiacfailure.
  • Polyneuritis manifest by weakness and paraplegia (partial or complete paralysis of the lower limbs caused by disease of the nervous system), loss of tendon reflexes, slight peripheral sensory loss and a high- stepping gait associated with foot drop – hence the reference to sheep.

Edible Plants

Bob Shoebridge

Our knowledge of native Australian edible plants is sketchy due to the early destruction of Aboriginal culture. Disease, genocide and active discrimination, coupled with very little being recorded by the invading Europeans, has left us with a limited number of known edible species and often these were recorded by a single, ill-informed source. Therefore early records of edible plants need to be treated with some caution, since many of these plants require complex preparation before they can be eaten, eg mangrove seed.

There is another problem that no apparent selection had been made by the Aboriginal people of plants for a better-yielding food staple. Probably, Australian native plants will never form a food staple with, perhaps, the sole exception being the macadamia nut – its commercial viability being due to the Americans!

Toxins

Before eating native plants it is a help to know the array of poisons which can confront you. If it is natural it is not necessarily safe. Toxins tend to be in family or genus groups; some of the major ones are:

  • Glycosides: These work on the heart, and cause vomiting and purging. Solanaceae and many plants with milky latex sap, eg Apocynaceae, have glycosides.
  • Serotins: To check for this toxin, grind the plant, shake vigorously with water or boil, then stand. If the resulting froth is stable after half an hour, reject the plant as it contains the toxin. Nicotiana, Duboisia and Derris all have this poison.
  • Cyanide: Species containing this poison often taste and smell of benzaldehyde (bitter almonds). Many nuts have cyanide which can be removed by a process of boiling and washing.
  • Alkaloids: These are often very bitter and work mainly on the central nervous system. Alkaloids are found in Solanaceae and Senecio.
  • Oxalic Acid: Comes in two forms: one burns the mouth whilst the other combines with body calcium to form kidney stones. The soluble oxalates are usually sour, and the main plant families containing this toxin include Polygonaceae and Oxalidaceae.

Unfortunately, toxin levels can vary from year to year, concentrate more highly in different plant parts, and be influenced by plant maturity. People can differ in their reactions to plant poisons.

Some poisons have a cumulative effect: for instance, the toxin in ferns destroys body vitamin B but is dangerous only if normal levels of vitamin B are not maintained. Eat foods rich in this vitamin whilst
consuming ferns.

Many fungi are edible although quite poor in terms of nutrition, ie vitamins, protein, etc. If unable to be positively identified they are not worth eating, as the poisonous varieties are extremely toxic and heat stable.

Nutrition

The major human food requirement is energy (fat and carbohydrates). Much Australian flora either has low nutrient density or may be difficult to gather in large quantities.

  • Shoots and berries are the easiest to gather, since large quantities can be collected on the run, need no preparation, and are highly digestible. Berries also form a valuable source of water.
  • Leaves contain too much cellulose to be a good food source. Approximately 11 kg would need to be eaten to satisfy daily requirements.
  • Bulbs, tubers and rhizomes are energy intensive to dig out and prepare, but they do have a high nutritional status.
  • Seed has high food value, but presents some difficulties in collection and preparation.
  • Much of our flora yields good quantities of nectar, and some flowers such as Wahlenbergia can be eaten whole.

Some Edible Plants

Macadamia nuts (Proteaceae) are the basis of major industries both in Australia and overseas

  • Orchidaceae: virtually all bulbs are edible.
  • Myrtaceae, Proteaceae and Xanthorrhoeaceae: are excellent sources of nectar. Proteaceae seed is also edible.
  • Epacridaceae: all soft fruits are edible and some flowers contain useful quantities of nectar.
  • Solanaceae: generally a family to avoid. Some species which are edible need to have very ripe fruit.
  • Asteraceae: most of the daisy group (the major exception being Senecio) are edible, if not palatable.
  • Grasses and Sedges: have seeds, rhizomes and shoots which can be used after a fair amount of preparation.
  • Ferns: the tips (fiddles) can be used following removal of the hairs. The rhizomes can be pounded and baked. The pith of tree ferns can also be eaten. Beware of the vitamin B destroying properties of ferns.

Some Dangerous Plants

Photo: Brian Walters

Senecio magnificus – Camel Weed or Tall Yellow-Top.
Family Asteraceae.

Hardy perennial medium sized shrub from most drier areas of Australia. Senecio species contain pyrrolizidine alkaloids which primarily affect the liver. Fireweed – S. madagascariensis, is a common exotic weed in NSW which is also toxic to humans and stock.

Photo: Brian Walters

Macrozamia communis – Burrawang.
Family Zamiaceae.

The seeds contain toxic compounds which have caused fatalities to both humans and livestock. The aborigines developed a method of vigorous leaching to remove the toxins and most species of Macrozamia were an important part of their diet. There are about 25 species of Macrozamia endemic to Australia.

Photo: Mary Louden. Qld Children’s Health

Castanospermum australe – Morton Bay Chestnut or Black Bean. A large, rainforest tree from northern New South Wales and Queensland. A member of the “pea” family which has yellow and red pea flowers followed by very large pods (up to 25cm long) each containing several large seeds. The compound Castanospermine is an alkaloid extracted from the seed of the Black Bean tree. It is found in all parts of the Black Bean tree but the content of the seed is especially high. It is easy to extract the alkaloid from the seed, as it is water soluble – the aboriginal people found this out a long time ago. The compound inhibits the actions of the enzyme that breaks down the sugar, glucose. It can cause vomiting and diarrhoea.

Photo: Brian Walters

Solanumsturtianum – Thargomindah or Sturt’s Nightshade.

Widespread in Central Australia. Solanum is a very large genus of about 1700 species with about 80 species native to Australia. Economically it is an important genus as it includes a number of human food crops including potato, tomato and egg plant.

The Australian species include important “bush tucker” plants (eg. Solanum ellipticum) but they also include species with poisonous fruits (including the fruits of Solanum sturtianum).

Strychnos nux-vomica – Strychnine Tree – Is native to Australia and SE Asia.
This medium sized tree’s fruit has highly poisonous seeds that are neurotoxic, causing convulsions, paralysis and even death. The blossoms can also be toxic and contain alkaloids strychnine and brucine.

Photo: J.M.Garg Wikipedia

Excoecaria agallocha – Thillai, milky mangrove, blind- your-eye mangrove and river poison tree. Found in tropics and sub-tropics in northern NSW,. QLD and through SE Asia to India. The plant’s chemical defences include include diterpenoids, triterpenoids and flavonoids. Even dried and powdered leaves retain the poison and can kill fish very quickly. The milky exudate produced by most plant parts can cause intense pain and temporary blindness if it gets into the eyes and painful blistering on other sensitive body parts.

The vapour inhaled while collecting this plant is extremely irritating, producing a burning sensation in the throat accompanied by sore eyes and a headache.


Largest Spotted Gum

Located within a State forestry reserve at Termeil, between Ulladulla and Batemans Bay on the south coast of NSW (and only 5 minutes off the Princes Highway), the State Government incorporated this tree (‘Old Blotchy’) into the Murramarang National Park in 2012. Estimated to be in excess of 400 years old, it is still within optimal condition and vigour. Now listed on the National Register of Big Trees, it is well known throughout the local district having long been named ‘Old Blotchy”.

‘Old Blotchy’

The tree is measured as 59m high, with a crown spread of 30m and a stem circumference of 10.7m diameter (as of 2008). The primary limbs start at 30m above the ground, but the diameter of these limbs ranges up to 1m and the extent of inosculation (self grafting between the limbs) of these limbs is unusual. Surprisingly, few cavity openings or hollows appear to exist within a tree of such age, however the height and mass of the crown could surely contain more that are obscured from the ground.

Warick Varley from ASGAP Eucalyptus


Stringybark is tough as old boots (and gave us the word ‘Eucalyptus’)

Eucalyptus obliqua. Photo: ANBG EUCLID

Few eucalypts are as versatile, varied and valuable as messmate stringybark. It was the first eucalypt to be scientifically named, and in fact gives us the name “Eucalyptus”.

Gum trees had been seen and collected on earlier expeditions, but a specimen collected on James Cook’s third expedition to Bruny Island off the Tasmanian coast was sent to the British Museum, where the French botanist Charles Louis L’Heritier de Brutelle named it and then published it in 1788.

L’Heritier named the specimen Eucalyptus obliqua, and so messmate stringybark is the first named and now type specimen for all Eucalyptus species. Because of the little caps covering the buds of this specimen , the name eucalypt was derived from the Greek eu, meaning “well”, and calyptos, meaning “covered”. Meanwhile, the asymmetrical or oblique leaf base gave us the description obliqua.

The name stringybark comes from the fibrous stringy bark that grows on the trunk of the tree, but no one knows the origins of the name messmate, which is also applied to several other eucalypt species.

E. obliqua is also commonly known as messmate, stringybark, browntop, Tasmanian or Tassie oak, or browntop stringybark. It is widely distributed through southeastern Australia, growing in Tasmania, Victoria, South Australia and much of New South Wales, almost to the Queensland border.

It is usually a tall straight forest tree that can reach heights of 80m or more, and girths in excess of 10m. It grows in higher and wetter habitats and often grows around other eucalypts such as E. regnans, E. delegatensis, E. viminalis or E. radiata.

Study Group October 2012


Parramatta and Hills District Group

SECRETARY: Caroline Franks

Email: apsparrahills@gmail.com