[Front Page] [Features] [Departments] [Society Home] [Subscribe]

Electronic Mailbox

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.

Reproduction of Native Australian Plants

I am a Year 11 student, and I am currently completing a Biology assessment on native Australian Plants. I was recommended this address and I am having trouble finding the answer to the following question, which I am hoping that you can answer.

How do the following plants reproduce?

	Acacia pycnantha (Golden wattle) Anigozanthos manglesii (Mangles kangaroo paw) Telopea speciosissima (Waratah) Clianthus formosus (Sturt's desert pea) Dendroblum bigibbum (Cooktown orchid) Callistemon macropunctatus (Scarlet bottlebrush) Banksia integrifolia (Coast banksia)

Greg Willis
gwillis@atu.com.au

Well... this is fairly basic but I hope it helps.

• A.pycnantha - regeneration from seed, usually after a fire which cracks the hard seed coat. The seed is released annually.

• A.manglesii - regeneration from seed and also from the underground rhizome. The seed is released annually.

• T.speciosissima - regeneration from seed and also from the lignotuber at, or just below, ground level. The seed is released annually.

• C.formosus (now called Swainsona formosa) - as for Acacia. The seed is released in the same season that the plant flowers (it may not flower every year if there are long periods without rainfall).

• D.biggibum - regeneration from seed or by offshoots.

• Callistemon macropunctatus - regeneration from seed which is retained on the plant in woody capsules for many years . The capsules open to release the seed after the plant is killed by a bushfire.

• B.integrifolia - regeneration from seed which is released annually (this is in contrast to most banksias which retain the seed on the plant for many years, similar to the bottlebrush).

Banksia grandis - not so difficult???

I have just been reading Australian Plants Online (which I always enjoy very much) and would like to comment on your reply to a query by Catherine Malcolm about growing some plants in Yarraville, especially Banksia grandis (Electronic Mailbox, June 2000).

I just wanted to let you know that I thought you were a bit cautious about Western Australian banksias in Melbourne. The bull banksia (B.grandis) that she was interested in growing is, in fact, quite a good one among the WA banksias to grow in Melbourne. I have 50 of the 62(?) WA Banksia species in my garden on the back slope of the Dandenongs, and have found B.grandis to be among the hardiest and most adaptable. I have four plants of this species and all are doing very nicely, even though some of them are not in full sun all day.

The soil in my garden is friable and well drained but contains a fair bit of clay and loam - definitely not sandy. B.grandis certainly differs from most other available WA banksias by growing into a mid-size tree with a definite trunk around which other lower plants can be planted. One of my specimens is in a fairly shaded spot - that was a deliberate experiment after reading that B.grandis often occurs as an understorey specimen in tall eucalypt forests. So I planted one in an area where several mountain ash (Eucalyptus regnans) cast a fair bit of shade. It grows slower than its siblings with the sunnier spots but has adapted OK.

As to longevity, there is a fairly old, mature specimen at Karwarra Gardens on top of the Dandenongs (or at least it was there two years ago last time I visited). That's quite a cold wet site and the plant was/is in a semi-shaded spot, but nevertheless coped well for many years evidently. Mine have made it to 8 years of age so far.

The only trouble I had with the bull banksia was that I could not get hold of a plant and had to order seeds from a WA supplier (Nindethana) and grow seedlings myself - which was no trouble.

Banksia grandis is very susceptible to jarrah dieback/cinnamon fungus (Phytophthora cinnamomi) in its native habitat. In fact, it often is one of the first species to die in an area under attack. Its susceptibility makes it all the more important that this plant (and many other western Proteaceae) be brought into more widespread cultivation. And to boot, it has splendid shape, leaves, and flowers!

Hans Griesser
Melbourne

Thanks, Hans, for that detailed response. Whenever I visit Melbourne, I become extremely jealous of the range of plants from Mediterranean-type climates that can be grown there. I've never attempted B.grandis here in Sydney - has anyone managed to get one to grow in more humid climates?

Not so Mousy??

I read with interest Neil Marriott's "Short Cut" about his Tumut grevillea, G.wilkinsonii (Australian Plants online, June 2000). I bought a plant last Autumn, repotted it into a larger pot, and left it in my greenhouse pending the construction of a garden. It produced 3 flowerheads, 2 of which set seeds. I don't think that native mice would have been able to reach it, as it was on a steel table, away from walls. So, perhaps the secret of its pollination deepens? Select the thumbnail image or highlighted name for a higher resolution image (37k). Photo: Neil Marriott

Roslyn Joseph
JRJoseph@bigpond.com

Just shows we still have a lot to learn. I know Neil will be interested in your observations.

Sending Seeds Overseas

My names is Vladimir Jurganov (Novosibirsk, Russia). I and may friends cultivate roomplants and attempt acclimatize some ekzotic plants en our country.

We're very interested in plants of your region. In first turn the question is Proteaceae, especially - Banksia (ericifolia, coccinea, collina, dentata, media, oreophila, serrata, quercifolia, nutans, hookerana, etc), Leucadendron (pubescens, floridum, dregei, etc), Leucospermum (formosum, patersonii, reflexum, etc), etc. Moreover we like other plants: Acacia, Metrosideros, Melaleuca etc.

We want receive, if it is possible, seems of the plants. We need an small quantity (10-20 seems) of the species.

Unfortunately, because of financial problems in our country, we can't buy the seems. Hence, we either must hope for your benevolenceor offer to you change to seems of plants of our flora.

I'm begging pardon for my poor English.

Vladimir Jurganov,
juve@aport.ru

Compared to my Russian, your English is fantastic!!

Just as a point of clarification - Leucadendron and Leucospermum are not Australian genera. They occur in southern Africa.

We receive similar requests to this from time to time but, unfortunately, it's not one that I can respond to favourably....for a couple of reasons....

While most of the Regional groups of the Society maintain seed banks for the benefit of their members, ASGAP, as a purely administrative body, does not have access to seed that we can supply on request. We have to rely on people either joining a Regional group and accessing the Group's seed bank or contacting one or more of the commercial suppliers listed on the web site.

There is, however, a bigger issue involved and that is....Should the Society send seed to other countries when we have no knowledge of that country's import restrictions and, more importantly, when we don't know whether the seed has the potential to become a pest species in the other country? Perhaps the chances of an Australian species becoming a weed in Russia are small - I just don't know and I certainly don't want to take the responsibility.

And it's not just the seed - we don't have any way of knowing if the seed is contaminated with micro-organisms such as fungi which could also become a problem.

The potential problem of invasive species being sent by mail is causing concern to Agricultural and Natural Resource managers who recently held a workshop in Perth to formulate ways of addressing the problem. A report on the workshop can be found in "First Cuttings".

Fan Flower in the Big Apple!

Please help....I need some friendly advice!

I live in New York City and in the spring I purchased a purple fan flower (Scaevola aemula) that was 3/4 dead (purchased only because it was indicated it was purple...there were no flowers) but I thought that with tender loving care perhaps I could bring this little "critter" back to life. Lo and behold, the TLC gave me a most beautiful specimen which stands as number one amongst all the other flowers that I have.

My only problem now is that I understand that it is an annual and will not bloom again next year. It is not planted in the ground...but I have roughly 18 metres (60 feet) of window boxes and numerous large pots on my deck. Select the thumbnail image or highlighted name for a higher resolution image (37k).

Inasmuch as I know, my chances of finding this plant again is perhaps one in a half-million, could you please tell me...

• Can I gather seeds?
• When and how?
• Must I propagate it from cuttings?.....
• or whatever else I could do to make sure I have this plant on my deck again next year.

Also, do you know if this comes in other colors...do you know of places that sell this type of plant retail (not wholesale) in the New York City area. I just happened to pick up this one very small container at a "junky" variety store.

Any information you can supply will be greatly appreciated.

athaas@email.msn.com

I never ceased to be amazed where Australian native plants keep cropping up. A Scaevola growing in New York City - who'd have thought......

Well, there's good and bad news......

It's not an annual but can live and keep flowering for many years. However, because it's a widespread species, it's a bit variable in growth habit and reliability and may be short lived.

It's unlikely to set seed and, in any case, seed is not easily germinated. It does, however strike easily from cuttings.

Take a look at the info on the web site. You might also find the plant propagation pages useful.

Banksias in the USA

I am living in the US and I don't know anybody I could ask the following question: I have a few Banksia integrifolia and Banksia spinulosa. They are growing very well and are now about 70 cm. high. I see that they are growing straight up and don't show any sign of branching. Shall I let them grow and wait, or shall I snip their growing points? I hope you will be so kind and help me. Select the thumbnail image or highlighted name for a higher resolution image (37k).

Rudolf H. Rahn
rudolf_rahn@yahoo.com

Well - I'm not sure that there's a right or wrong answer here....

The B.integrifolia is a small to medium tree...you could prune the growing points but I'd let it do its own thing.

The B.spinulosa is a bit different. Generally it's a small to medium shrub but there is a form (sometimes known as a separate species B.cunninghamii) which does grow as a large shrub or small tree. Either way you can take out the growing points to promote branching without problems but they will probably branch of their own accord. The lower growing forms develop a lignotuber so they should tolerate very severe pruning to ground level later on if you find that the plants are growing with a "leggy" habit. New branches should develop from the lignotuber. The larger form doesn't have a lignotuber so is better trimmed annually rather than severely pruned later.

A Pollination Project

I have recently been given a year 11 biology Assesment task which requires me to research and investigate a wind pollinated angiosperm and an animal pollinated angiosperm.

I was hoping that you could assist me in my research. Any help would be much appreciated.

Zoe Cunningham,
Sydney

A similar question was received from Keelyann Thomson of the same school.

I don't have the scientific expertise on hand to give detailed answers but I've listed a few references below that might help.

Generally, the most common wind pollinated flowering plants are grasses. Common examples are Kangaroo Grass (Themedia triandra) and Wallaby Grass (Danthonia sp.). Wattles (Acacia sp.) are mainly wind pollinated but insects may also be involved (it's possible that wind pollination is involved with many plants that are mainly pollinated by animals.)

Common plants pollinated mainly by animals (birds, insects and small marsupials) are Banksia, Eucalyptus, Callistemon, Melaleuca, Grevillea.

Take a look at these web sites:

• Australian Plants on line: "Plants, animals and sex"
• CSIRO Information:
  Wind pollination - mainly aimed at pollen counts for people who are allergic to certain pollens but it also lists a range of wind pollinated plants.
  The sex life of plants - has some useful info.
• Palm and Cycad Society of Australia:

Wanting to Grow Red Cedar

I'm thinking of planting a few Australian Red Cedar trees (Toona ciliata) and was wondering if there is anything that can be done to minimize or stop the Red Cedar Tip Moth from attacking the trees.

I have a few acres of land near Sydney and thought I would plant 50 or so trees. I'm not doing this as a plantation and I was planning to just randomly plant the trees over the whole property, in the bush. I was given the idea by a comment someone made that these trees are not attacked by white ants, is this true. Many of the trees on my property have been severely damaged by white ants.

Any comments or suggestions would be appreciated.

David Irwin
davidi@ihug.com.au

The best I can do is suggest you take a look at the CSIRO's media release on tip moth research....it includes photos of the larvae and the effects on the young trees.

Cleistogamous Pavonia

First ecuse me for my english but it's difficult for me to scribe in english.

I see on your site that Pavonia hastata frequently make seems without flower. It's the case of mine in south of France and I have not one flower actually but a lot of seems (about 50 at the same time). Here nobody know what to do! Select the thumbnail image or highlighted name for a higher resolution image (26k).

Also if you know and can say to me what the matter I will be very happy and thanks you.

It's position: full sun for 4 hours in the afternoon, lot of NPK and lot of water this year.

And for 3 years in my garden....first flowers very beautiful, second a lot of seems and some flowers, third - only seems.

Richard Gautier
richard.gautier@libertysurf.fr

No need to apologise for your English - You've made the question quite clear. Unfortunately the answer won't be!

There's really nothing much that you can do to make the flowers open. It's just a characteristic of the plant and is referred to as "cleistogamy". It may have something to do with climate and/or growing conditions but I think it is more or less genetic.

I find with my own plants that flowers start to open late in the season so your plant may do the same.

For those not familiar with the plant, you can find out more on the web site.

Looking for a Gum Tree

We live in a suburban area and wish to plant a gum tree but don't want to make a mistake with size and which one. We have asked at a couple of native nurseries and seem to get conflicting information. We want something between 5 - 10 metres, flowers profusely to attract birdlike and has a trunk with canopy so we can see past to our aviaries and existing native garden.

We have a couple in mind but what would you suggest?

We have started to attend our local SGAP meeting and they have suggested Eucalyptus torquata or Eucalyptus forrestiana, the fuschia gum (which we already have).

We hope you can give us some guidance so we don't plant the wrong thing.

Robert Biro & Debbie Bergheim
etonwood@geelong.hotkey.net.au

Well....actually you're already doing what I would normally advise.

As I'm based in Sydney, I rely on local Australian native plant groups to advise on plants suited for local conditions. I don't have any special access to other information but, from what I have seen over the years, Eucalyptus caesia might also be worth considering in your area. Talking to members of the local group is the best advice I can give.

Select the thumbnail image or highlighted name for a higher resolution image (33k).

How Long for a Black Trunk?

I have two grasstrees (Xanthoarrhoea species) in my garden which are very large and 'leafy'. I would like to know how and when will these develop a black trunk. They are approx. 5 years old and have the thickest foliage, one seems to be shooting in 3 directions but neither show any trunk at all.

Do I need to burn something or just leave alone and wait???

Hope you can help.

The bad news is that there isn't anything that you can do to make grass trees develop trunks. They are extremely slow growing plants and the ones you see in the bush with tall trunks may be 50-100 years old or more.

The only practical way to get a "trunked" grass tree is to buy one of the mature ones available in nurseries or be prepared for a very long wait!

[Front Page] [Features] [Departments] [Society Home] [Subscribe]

Australian Plants online - September 2000
Association of Societies for Growing Australian Plants