Claw-like eucalyptus parasite?

[Micromegas]

Went walking in the Adelaide Hills yesterday and noticed all these strange diseased growths on many eucalyptus trees. Where a branch should be growing normally at the tip, it instead formed a really terrible looking gnarled, multi-stemmed 'claw', the wood turning black and the leaves getting very yellow and sick, eventually leading to death of the branch (but not the whole tree).

This was really despressing to see. Some trees had more than one infestation, or almost totally diseased, most trees in some areas having at least one. Many trees had a leafless and black 'claw' just dangling in the air, forlornly, with no more leaves. However, in areas of recent bush fire the vegetation is free of the parasite (?) and growing back very vibrantly.

I would really like to know what is going on here, it was definately a blight on the landscape. Perhaps someone knows what I am talking about. It seemed to be some sort of parasite or disease that attacks the branch tip and causes it to grow erratically and then atrophy.

How does it get here? Is it indigenous? Can anything be done, outside of a fire?

Thanks

Micro

[AndyAmine.]

Some kind of gall?

The acacia wasp gall you see around here is pretty crazy stuff to see.

[incognito]

nah 'mistletoe' its is a parasite. a parasitic plant. i bet my 10 beans anyway. dont know the botanical name. can look up for u. apparently the sign of a healthy ecosystem.

Edited February 6, 2008 by jono

[Micromegas]

Wow thanks for that. I was really agitated by seeing this all over the trees but looks my intuition has been fooled. I was convinced it was dying eucalypt leaves, but seems these strange growth were plants in their own right with leaves that just looked like dying eucalypt leaves - yellowed and slightly succulent, drooping. Mistletoe indeed, thanks for the heads up. Looks like A. miraculosa or A. pendula according to the internet, but since there are so many how would i know. Seems they are an important species in the ecosystem in terms of plant food and habitat, but can also get out of hand. I think in this park they were slightly more common than desired, as they were affecting some large host trees quite dramatically and occurred prolifically... however I think that the occasional fire must be important in regulating spread, the most affected areas being valley walls and crevices. Apparently human mismanagement of ecosystems has causes upset to the usual balance of occurance... no surprise there...

Thanks, lots to learn,

Micro