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The following have been selected from the questions received on the ASGAP World Wide web site over the past few months. You're welcome to comment on any issue concerning Australian native plants....growing, propagating or appreciating (even loathing!) ... anything.
If necessary, bung a message in a bottle if your net connection goes down!!
....and, if you'd like to contact any of the correspondents and no email address is listed, please feel free to do so through the editor.
Kurrajong Distribution
The San Luis Obispo Botanical Garden which features plants of mediterranean climate areas of the world, has received a plant labelled Brachychiton populneus. The Royal Horticultural Society's Dictionary of Gardening says it is found naturally in Queensland and New South Wales. The new The Western Australian Flora indicates that it is found on the Geraldton Sandplain and the Swan Coastal Plain. I need verification of these Western Australian locations.
Can you give it to me or at least direct me to someone who can?
I will be forever grateful.
Malcolm G. McLeod
Obispo, California, USA
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Select the thumbnail image or highlighted name for a higher resolution image (33k). Photo: Keith Townsend. |
Brachychiton populneus (Kurrajong) occurs naturally in Victoria, New South Wales, Queensland and (possibly) the Northern Territory. It does not occur naturally in Western Australia but has become naturalised in some locations there.
By coincidence, a few days ago a correspondent sent me the following extract from the Australian Journal of Ecology, October 2000. I think it clarifies the position (at least for the Swan Coastal Plain) but you could probably get first hand advice from the Kings Park Botanic Garden in Perth.
Ecological characteristics of Brachychiton populneus (Sterculiaceae) (kurrajong) in relation to the invasion of urban bushland in south-western Australia
Marcelle Buist, Colin J. Yates and Philip G. Ladd
Brachychiton populneus (Sterculiaceae) (Schott et Endl.) R. Br. (kurrajong) is a small tree that occurs naturally ranging from southern Queensland to Victoria. It has been widely planted as an ornamental tree in south-western Australia. In Kings Park, B. populneus has moved from cultivation to become a weed in the adjoining bushland reserve. The aim of this study was to examine the ecology of B. populneus and the Kings Park environment in order to identify the particular conjunction of characteristics that have led to the species becoming a weed.
The highest density of kurrajongs (69.3 trees ha-1) was observed in the most disturbed area of Kings Park, and there was a strong relationship between density of B. populneus and disturbance (P = 0.058). The most striking feature of the invasion was the tendency of B. populneus to occur beneath other tree species, and this was attributed to birds feeding on transported fruit in trees and rats building seed caches at their base. Mature trees produced large amounts of viable seed, but rates of seed predation were high. Weevils, beetle larvae and omnivorous vertebrates such as Australian ravens, magpies and introduced black rats were observed eating seeds. The foraging behaviour of the vertebrates may facilitate the dispersal of seeds for relatively long distances away from parent plants.
Seeds that escape predation form a transient seed bank and germinate with the onset of the winter rains. Early in their development, seedlings allocate resources to form a large tap-rooted tuber that has substantial starch and water reserves, allowing seedlings to survive the long dry and hot summers in Perth. The study observed that B. populneus could survive at least one fire by resprouting from basal dormant buds.
Brachychiton populneus appears to have become a weed in Kings Park because, first, it is dispersed widely into new sites through the foraging behaviour of vertebrates and once germinated has no grazing pressure, and, second, its development of a root tuber and ability to resprout means the seedlings are resilient in this frequently disturbed Mediterranean environment. While management of existing plants is relatively straightforward, continued vigilance will be required to avoid reinvasion.
I hope this helps.
Yellow Tips
I live at the back beach of Rye in Victoria at St. Andrews Beach. Over the last 2 years I have planted a native garden. The problem is about a fifth of the plants have gone yellow on the tips. I know we have quite acidic soil but the plants are suited to this area. Is there something I can add to the soil to improve their condition? I don't want them to die!
Vanessa Paulzen
Rye, Victoria
This is not an easy problem to diagnose, particularly without seeing the plants.
All native plants don't have the same nutritional requirements so it's impossible to advise whether or not something should be added to the soils without knowing what species or cultivars are involved, what type of soils are present, what the drainage is like, whether fertilizing has been carried out and what sort of fertilizer has been used.
You would probably be best advised to get some advice from a local nursery - perhaps take a sample of the foliage so that they can see what the problem is. The best I can do is provide a few general guidelines:
- Yellowing of foliage can be caused by many factors but often indicates a nitrogen or iron deficiency. You could try applying iron chelates (available from nurseries) according to directions to see if that helps. This is unlikely to cause any damage to the plants. If that doesn't work a soluble nitrogen fertilizer might help.
- If the soils had been previously fertilized for vegetables or exotic plants, there could be high residual nutrients in the soils which could adversely affect the plants. Many of the commonly grown Australian native plants are very sensitive to phosphorus and too much can be toxic. There are low phosphorus, slow release fertilizers available (often labelled as being suitable for natives) and these are the safest to use particularly with plants in the Protea family (eg. Banksia, Grevillea, Hakea). Other plants such as bottlebrushes and Melaleuca are less sensitive.
- Finally, check that drainage is OK. Generally constantly wet (rather than moist) soils are likely to cause problems.
High Climbing
I hope you can help me. I am searching for a vine or creeper to completely cover an unsightly 8 foot chain mesh fence 20m long. I would prefer a fast growing plant, with thick foliage and (hopefully) flowers, that is tolerant of pruning. The vine would also need to keep its leaves all year round to avoid losing privacy and aesthetics.
I live in Brisbane and the soil is a little poor in this particular area (if you could provide tips to en richen the soil before planting I would be most grateful). I would appreciate any information you could supply me.
Garry Mahon
Brisbane, Queensland
There are lots of climbers suited to your climate. I would suggest Pandorea jasminoides (top, left - sometimes called "Bower of Beauty" - stupid name!)
Other possibilities, depending on availability, could include:
- Aphanopetalum resinosum - very attractive glossy green foliage but fairly insignificant flowers.
- Cissus antartica (native grape) - bears black edible fruits that can be made into a wine.
- Faradaya splendida (bottom, left).
- Jasminium suavissimum (bottom, right - native jasmine). Highly scented.
- Milletia megasperma (native wisteria).
- Passiflora species (native passionfruit). Passiflora aurantia (centre, left); Passiflora cinnabarina (centre, right)
- Pandorea pandorana (Wonga vine) - several colours available including pink, yellow and white. (cultivar "Golden Showers" - top, right)
- Tecomanthe hillii (Fraser Island Creeper).
Check out native nurseries in your area from our web site
I wouldn't be too concerned about enriching the soil - some slow release fertiliser at planting should be sufficient with a follow up after flowering, if the plant looks like it needs it.
Beware the Gympie Bush!
I recently heard a broadcast where one of the participants mentioned a tree or bush called the gimpy gimpy (the spelling is phonetic as there was no written info I can find). The person said that if one were to touch the plant he would experience pain "for years". I thought our cactus in New Mexico were nasty!
Can you direct me to any information on this plant?
Dale,
New Mexico, USA
It's actually spelt "Gympie" and pronounced "gimpy" (Gympie is a town in central, coastal Queensland).
I don't know how nasty the cacti in New Mexico are but, if they are as bad as "Gympie Bush", then they are bad indeed!
Gympie Bush is Dendrocnide morioides. There are about 6 species of Dendrocnide in Australia and another 30-40 in other parts of the world. As far as I know they are all stingers but D.morioides is the worst of the Australian group.
It is a medium sized shrub with large oval shaped leaves. It lives in rainforests all down the Queensland Coast and into north-eastern New South Wales. The plant has stinging hairs on the stems and leaves and the sting can be excruciating for several days and then may reoccur over a period of months.
Apparently there are records of horses being killed by an encounter with a clump of the plants.
There are actually some masochists who are interested in cultivating D.morioides. It apparently strikes readily from cuttings but propagation requires a degree of dedication bordering on the insane!
Smoke Bush
My 7 year old daughter is researching the smoke bush and we are finding it hard to find information on it.
Does it have a different name? and could you point us in the right direction for information?
Andi Kelly
Western Australia
I'm not sure what sort of info you need but here are some brief details.
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Select the thumbnail image or highlighted name for a higher resolution image (52k). Photo: Australian Plants Soc (NSW)
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Smokebush is not a single plant. The name is generally applied to members of the genus Conospermum. There are about 36 species in the genus, most of which occur in the south of Western Australia but there are also some in Queensland, New South Wales, Victoria, South Australian and Tasmania.
Conospermum is a member of the Protea family of plants (known as Protaceae) and is related to much better known plants such as Banksia, Grevillea and waratah.
The name 'smokebush' probably best applies to some of the Western Australian species and it refers to the general appearance of some of the species when viewed, from a distance, when in flower. The appearance is of puffs of white smoke. Some western species are used for cut flowers in the floristry industry.
The best general references on the genus are:
- "Banksias, Waratahs and Grevilleas" by John Wrigley and Murray Fagg (Collins Australia)
- "The Encyclopaedia of Australian Plants" Vol.3 by Rodger Elliot and David Jones (Lothian)
You may find these in a local library.
I found the following resources on the internet - they may be a little more detailed than you need:
An odd looking Euc!!
Hello, I am a South African interested in eucalypts.
I believe over 90% of our Eucalyptus here are E.saligna and it is my favourite tree. I planted one a year ago, about 750 mm tall, and it is already over 3 metres. Its leaves are slender and opposite and sessile, and all the branches are opposite.
Since planting it, I have taken an interest in young plants, and nearly all the wild ones growing here are radically different, looking like mature trees.
Recently I have found a few specimens the same as mine, and some intermediate. About 2 weeks ago I planted a "normal" E.saligna at my factory, but I am not expecting it to grow fast. This one is about 2,5m tall.
I want to confirm the identity of my opposite, sessile leafed plant. Can someone help me?
Dave Onderstal.
South Africa
I'm afraid its almost impossible to identify the plant at this stage. Identification really depends on characteristics of the mature plant (eg bark type, flowers, fruit shape, etc).
All I can say with some certainty is that the plant is unlikely to be E.saligna. All Eucalyptus species start out life with opposite leaves - the leaves usually change to an alternate arrangement as the plant grows. Sometimes the opposite, juvenile leaves are retained even as the plant matures (eg E.gillii - see photo) and in some cases both juvenile and mature leaves may be present even on quite large trees (eg E.globulus).
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The juvenile foliage of Eucalyptus gillii is retained on mature trees. Note the opposite leaves - typical of juvenile foliage on Eucalyptus species.
Select the thumbnail image or highlighted name for a higher resolution image (34k).
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However, with E.saligna, it's not usual for the juvenile leaves to be retained on a plant as large as yours and, in any event, the juvenile leaves of E.saligna are petiolate (stalked) not sessile (without stalks).
The other possibility is that the plant is an Angophora. These are eucalypts with opposite foliage.
Is this a Grevillea?
I wonder if someone may be able to identify what I think is a native Grevillea that I have found in recent weeks. Presently growing in reclaimed cattle country near Seaham (about 45 kms north of Newcastle, New South Wales).
The bush is only about 30cm tall in black gravelly loam amongst grasses. I'm not sure how tall it will grow.
I would appreciate an ID or name of someone who may be able to ID.
Ian Goodson
New South Wales
The plant is a Lomatia; almost certainly L.silaifolia. Lomatia is in the same plant family as Grevillea (the protea family or Proteaceae).
It's fairly common along the New South Wales coast extending into south-east Queensland and is usually a small shrub to a metre or so high.
Marram Grass
My name is Alex and i am researching marram grass for a school project.
I am 12 years old and I'm looking for information on who introduced it, when and for what purpose. The damage it has caused and how it has been eradicated.
I look forward to your response and thank you for the information.
Alex
Australia
Unfortunately I can't provide a great deal of information.
Marram Grass (botanical name = Ammophila arenaria) was introduced for coastal sand dune stabilisation purposes. It is apparently very useful for this purpose as it can successfully become established in shifting sands.
I'm not sure when it was introduced but there are reports of it being used as long as 100 years ago.
It was originally considered to be sterile (ie did not produce seeds) and would not spread. However, it has been found to produce fertile seeds in some areas and is now spreading from those areas into other areas.
I could find no useful information about its use and problems in Australia but the web site for the California Exotic Pest Plant Council provides some information on similar problems on the west coast of the USA (where the plant is called "European Beach Grass").
The article is fairly technical but you should be able to extract some useful information. Your project would probably benefit if you made some mention of overseas experiences with the plant to show that the problem is not just restricted to Australia.
Australian Mints
I would like to know the scientific names of the following native harbs: native mint, native pepperberry, native peppermint and forest berry herb.
Thank you.
Helen Huang
This question is not as easy to answer as it may appear because common names can apply to different plants. And some common names are not really commonly used!
- "Native mint" covers a whole range of plants in the Lamiaceae. Species of the genus Prostanthera are called "mint bushes" and there are about 60 species. Australia also has a few species of Mentha which is the genus which contains the common culinary mints. So there is no single species called "Native mint".
For more information see the Mint Bush Family Page on our website.:
- "Pepperberry" is probably Tasmannia lanceolata but it's more usually called "native pepper" or "mountain pepper".
- "Native Peppermint" is probably Mentha australis but there are a whole group of eucalypts known as "peppermints".
- "Forest berry" could be anything. I don't know of any plant with that common name but my guess is that it's Billardiera scandens, commonly know as "apple berry".
Sorry I can't be more definitive but many common names of Australian plants are ambiguous and confusing.
Poisonous Australian Plants
Hi my name is Halima. I am doing an assignment on poisonous plants in Western Australia. I was hoping you could provide me with the names of two poisonous plants and a description of what part is poisonous and what effect it has.
Halima
I think the best advice I can give is to refer you to the excellent article "Australian Native Poisonous Plants" by Dr Ross McKenzie.
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The family Solanaceae includes many plants that are poisonous and many that are important foods (eg. tomatoes, eggplants and potatoes). This is Solanum sturtianum a poisonous species from semi arid areas.
Select the thumbnail image or highlighted name for a higher resolution image (23k).
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The article is very comprehensive and covers:
- What is a poisonous plant?
- What do poisonous plants look like?
- Why are plants poisonous?
- Are native animals poisoned?
- History of plant poisonings
Plants that are Compatible with Eucalypts
Is there any truth to the suggestion that eucalypts produce some sort of toxin that prevents the growth of other plants in the root zone?
I wonder how poisonous eucalypts can be when I have to remove grass to plant my seeds and bulbs. If there's any poison, it doesn't seem to affect the grass! I also noticed that the soil under the eucalypt is with life. I saw bugs, centipedes, earthworms, beetles, grub worms and all sorts of crawling, creeping things. This surprised me because I had expected to find a sterile situation because of the eucalypt.
It looks like their reputed toxicity, if it exists at all, is greatly exaggerated.
Warren Jones
USA
In nature a whole range of plants grow in the roots zones of eucalypts. I am not aware of any chemical produced by eucalypts that discourages the growth of other plants.
By coincidence, I've just been advised of a web site (by San Marcos Growers in California) which contains specific advice and suggestions for planting under eucalypts. Basically the site suggests that "when planting under Eucalyptus, the primary factor limiting a succesful planting is competition. The chemical compounds in the leaves have long been thought to prevent the growth of other plants, but this now considered minor in comparison to the inability of most plants to compete with Eucalyptus for water and nutrients".
Well worth a look - and not just by growers in the USA!
Predators and Dangers
I have a question about plants in Australia that I was hoping you could answer.
I am doing a school project, so it would mean a lot to me if you could reply. For my project I am studying Australian plants and I was wondering what types of predators or dangers it would have. I have been having trouble finding information about my topic so it would be really helpful if you could answer it.
Student
USA
This is a fairly general question and the answer could probably fill a book! So I'll be fairly general as well.
Australian plants interact with a whole range of animals, other plants and climatic factors. In relatively undisturbed forests, woodlands, etc, the plants and animals are generally in a balanced ecosystem. That is, one part of the ecosystem doesn't become so dominant that it affects the health of the other parts.
However, when humans interfere with the balance (eg. by introducing pest species) the balance can be upset.
Here are some of the range of interactions between plants and other parts of ecosystems.
- Foliage grazing by animals - Plants are grazed by native animals such as kangaroos, wallabies, koalas etc. Generally these cause no severe damage to vegetation as a whole, although individual plants may be considerably damaged. However, in areas where pest species such as rabbits have become established, severe damage can occur over wide areas, even driving some plant species to near extinction.
- Fruit grazing by animals - Plants that produce edible fruit are used as food by possums, birds, etc. Generally these don't cause any severe threat to the plants.
- Grazing by insects - There are many insects which eat the foliage or wood of plants. These include caterpillars of butterflies and moths, wasp larvae, borers, termites, etc. Again, these do not cause severe damage in a healthy ecosystem. However, insects can reach plague proportions where humans interfere in the ecosystem. For example, widespread clearing of trees can mean that the few remaining trees become food for a much larger number of insects than normal. This can lead to widespread death of trees as has happened in the New England region of New South Wales.
- Parasitic plants - the most common of these are the various mistletoes which germinate on the branches of plants and extract their food for growth from the host plants. Usually mistletoes don't cause serious problems but, if too many mistletoes become established on a single host plant, the health of the host plant suffers - sometimes leading to death of the host. There are other types of parasitic plants which attach themselves to the roots of host plants.
- Pathogenic fungi - Many Australian plants are sensitive to the root rot fungus (Phytophthora cinnamomi). In some areas, Phytophthora has been spread from infected areas into areas where it previously did not exist, though spores which have become attached to tyres of vehicles or even on the shoes of humans. This has a devastating effect on susceptible plants and is a serious problem in forests of south Western Australia.
- Other fungi - Fungi have a role to play in the recycling of nutrients in a forest through hastening the decay of dead plants.
- Severe storms - These can destroy large areas of vegetation but damage is generally localised to a relatively small area.
- Fire - This can destroy vast areas of forests. In natural ecosystems, the plants have evolved to cope with fire through regeneration methods such as sprouting new growth from the root systems or from under the bark of trunks and stems. Other plants rely only on seed for regeneration and these types of plants can be threatened if fires occur too frequently (ie. before the plants have time to grow from seed to adult plants).
I hope this helps.
Moving a Bunya
I have an adult bunya pine (Araucaria bidwillii).....well, it has been an adult for at least 46 years, that's how long we have been on this farm.
Over the years I have tried to grow another from the little seedlings that pop up now and again under the tree. I have a seedling of about 20 cm at the moment but I am not game to move it yet. I would love to know when is best to attempt a transplant and what conditions I should move it to.
Lyn Harvey
Australia
Transplanting is always a risk but the cooler months are the best to make the attempt as this gives the plant a reasonable period to re-establish damaged roots before the following summer.
At 20 cm high, the plant is quite suitable for transplanting and provided you get an undisturbed root ball (as large as you can manage easily) it should transplant OK - but there are no guarantees.
Bunya pines are hardy plants so put the transplant in any location that you want (pre-dig a suitable sized hole first) - just make sure that the soil doesn't dry out. Perhaps sink a pot into the ground next to it and water into the pot so that moisture gets to the root system.
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Australian Plants online - June 2001
Association of Societies for Growing Australian Plants
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