Re: disappearing Angophora costata
John Atkinson wrote:
>
> At 20:30 Sunday 6/08/00 +1200, Moira wrote:
>
> Richard Starkeson wrote:
>
> >> Our local paper the Chronicle (derogatively referred to by the natives
> >> as the Comical) had a 3 line item in it today about the disease and
> >> death of virtually all of this tree in the vicinity of Sydney.
>
> This is a slight exaggeration, to say the least. Not many trees have
> actually died, at least not yet. But there's been serious dieback.
Hi John
I was hoping someone would give us a local perspective. Glad to know the
report is (for the present at least) an exaggeration. Your tree sounds
lovely. I hope the neighbours do also appreciate it. Saves them planting
one of their own!!
We had a scare a few years ago about the sudden death of ever so many of
our Cordyline australis trees in the Auckland area. It looked as if it
was going to spread through the country, but after a few years has I
think lost its virulence, and around Wellington, apart from one or two
trees (which may or may not have had the same problem) seems never to
have taken a hold. Even near Auckland I think some plants survived and
young ones are beginning to grow. They seemed to think thay had found
some sort of insect (leafhopper?) which was responsible, but don't know
if this was ever confirmed.
It makes one wonder what is the current problem with your trees. Could
it be pollution? (or more likely not straight pollution, but some
pathogen taking advantage of stressed trees). Or alternatively are you
having unusual weather? We certainly are right here. Wellington's July
has been among the dryest on record with only about a fifth of the
normal rainfall (We have actually started to do some outside watering -
in WINTER!!) In all the 45 years we have owned this property we have
never seen a real drought, but we are certainly wondering what is going
to happen come summer this time. Curiously, other parts of the country
have had either normal or unusually high rainfall (blame La Nina, I
guess)
> The genus Angophora has always (well, as far back as I remember) been
> separate from the genus Eucalyptus. You may recall that a couple of years
> ago, the splitters got busy and chopped Eucalyptus into three or four
> different genera. Well, a few months ago the lumpers struck back, so
> Eucalyptus now not only contains all it did before, but has also swallowed
> Angophora. So I guess it's now Eucalyptus costata, at least for the moment.
A wonderful game this splitting and lumping. I shall myself continue to
use the familar names until the situation settles down.
> Around Sydney, it often grows in very exposed coastal positions, often the
> only trees that will grow there -- rooting in narrow cracks in the
> sandstone rocks and forming beautiful windswept specimens a few meters high
> with trunks a meter or more across.
>
> But yes, like many eucalypts, it does tend to drop big branches, especially
> (but not only) in unusually high winds.
As you say this is no big deal with any Eucalypt or related species.
>
> > and also from frost when young.
>
> Hmm. It certainly grows prolifically in the sandstone parts of the Blue
> Mountains west of Sydney, where there are quite heavy frosts for several
> months of the year, as well as the odd snowfall. If it's frost-sensitive
> while young as you say, I guess it must be one of those eucalypts which
> don't germinate till the spring after they flower, so that the seedlings
> are well along by the time they encounter their first winter.
Quite a few gums are popular in NZ but many do seem pretty sensitive to
frost at first, though becoming increasingly hardy once established.
This is on a par with Citrus at the cold end of their range. We can, for
instance, quite happily grow mature Meyer lemons in this valley, but
unless our gardens are unusually sheltered they may need coveing through
winter for the first couple of years.
It was interesting to learn of nature's strategy, which you describe,
for dealing with cold.
Of the many (at least 20?) species of Angophora ("apple gums"), all
(AFAIK)
have the same interesting twisted form, but almost all have rough bark
rather than the smooth shiny bark of costata, with its beautiful
colouring,
especially when the old bark has just been spread. I believe there is
one
other smooth-barked species, which grows further out west in NSW. Is
this
A hispida?
No, according to the book hispida is definitely rough-barked.
Unfortunately my book only gives a selection of the best-known species,
sticking mainly to those already widely cultivated, so it doesn't
mention your other smooth species.
Nice to talk to you
Moira
--
Tony & Moira Ryan <theryans@xtra.co.nz>
Wainuiomata (near Wellington, capital city of New Zealand)
