Sunday 26 May 2013

Gymnosporangium confusum

Gymnosporangium confusum  Juniper Rust, (May 2013) (Nottinghamshire)

Friday 17th May 2013.  Not an ordinary day.  The previous day I'd received a text message from a 'fungi aware' friend that something was growing on her Juniper tree.  So, straight after work, I set off to view for myself and take some photographs.  This fungus was certainly different.  Growing in batches on the trunk and branches and not more than five feet off the ground.  Some of the fungus had developed a jelly like texture and was falling to the ground in little clumps. I took many photos including the jelly like substance in the grass. 

The fungus is difficult to describe.  It is mid-brown with mustard coloured powdery spores.  Slightly elongated tongue-shaped.

"In junipers (the primary hosts)  some species of the fungus form a ball like gall about 2–4 cm in diameter which produces a set of orange tentacle-like spore tubes called telial horns. These horns expand and have a jelly like consistency when wet. In other species the telia are produced directly from the bark of the juniper with no obvious gall formation or swelling[2] such as in G. clarvariforme . The spores are released and travel on the wind until they infect an apple, pear, or hawthorn tree."  Source Wikipedia.

After some research, it appears that a pear tree two years previously in an adjacent garden had been infected with Rust and cut down.  This now leaves the question of where will the spores travel within the next 4-6 weeks and what will it infect.  I will write an up-date if monitoring produces a result.

With grateful thanks to RR for his help in doing a spore analysis which enabled a positive identification and for undertaking research about Juniper trees so that we could come to the conclusion that all the facts fitted together ie this was a G. confusum which was growing on a specific Juniper which was a Chinese Juniper.
Even more exciting for us both is that this fungus has never previously been recorded in Nottinghamshire so will be added to the database.

A big thank you also to J O for allowing me to visit the garden and to take photographs.

Photographs of this fungus can now been see on Browse 4, Thumb nail panel 25 at