 <unk> , Amanita muscaria forms symbiotic relationships with many trees , including pine , spruce , fir , birch , and cedar . Commonly seen under introduced trees , A. muscaria is the fungal equivalent of a weed in New Zealand , Tasmania and Victoria , forming new associations with southern beech ( <unk> ) . The species is also invading a <unk> in Australia , where it may be <unk> the native species . It appears to be spreading northwards , with recent reports placing it near Port Macquarie on the New South Wales north coast . It was recorded under silver birch ( <unk> <unk> ) in <unk> , Western Australia in 2010 . Although it has apparently not spread to eucalypts in Australia , it has been recorded associating with them in Portugal . 
