Rare mushroom appears out of the blue

Of these, without doubt the most unusual blue decoration discovered in a local bower is an exotic mushroom, usually only found growing on the other side of the planet.

The curious case of the mysterious mushie began 10 years ago when Peter Marshall stumbled on a number of blue mushrooms while clearing blackberries from under a European plum tree on his farm at Reidsdale, about 14km from Braidwood.

"They were growing right in the middle of a rudimentary bower, hidden amongst the blackberries," recalls the Reidsdale farm forester. "I looked at my friend who was helping me at the time and said hang on, that can't be true."

By chance, Peter's friend, Todd Elliott, just happened to be a trained mycologist who promptly identified the specimen as a Lepista nuda, a blue mushroom native to Europe.

The discovery left the two men baffled.

"We wondered how on earth did it get here, Lepista nuda wasn't known to us in Australia at that time," says Peter. "It was a real puzzle".

But it is a mystery which Peter believes he eventually solved. Several years later while walking beneath a giant 140-year-old Cork Oak (yes, the same species as those planted in the early 1900s in Canberra and now part of the National Arboretum) in the yard of the historic Constable's Cottage in Braidwood, Peter noticed another of the blue mushrooms.

"I couldn't believe my eyes," says Peter. "Closer inspection revealed it was the same species I'd found in the bower on my farm back in 2010."

Peter's research indicates "it was likely shipped out in the 1860s as a seedling in a pot".

"This means the soil in the pot would have contained European microbes, likely including that of Lepista nuda," he reveals. Bingo!

The series of coincidences is not lost on Peter.

"The Cork Oak likely had the European fungus in its root system since 1880 or so and while fruiting several years ago a male bowerbird which loves blue things collected the mushroom for its bower which he just happened to build under some European plum trees which allowed the mushrooms to infect its roots, and which a few years later fruited at exactly the same time a mycologist happened to be cutting blackberries right next to it." Remarkable indeed.

According to the Atlas of Living Australia (a comprehensive online repository of information about Australian plants, animals, and fungi) there are only a handful of other observations of Lepista nuda in our region, most reported in the last year. I wonder if they are the result of dispersion by another (or the same) industrious bowerbird?

Still in Braidwood, over the past couple of months this column has received a handful of missives from readers asking about the origins of hundreds of small sand-filled holes in the town's leafy Ryrie Park, a popular stop-off point for Canberrans en route to the coast.

"Is there a gopher on the loose in Braidwood?" muses Jack Smithers of Kambah.

It turns out our mushroom detective Peter Marshall is also best placed to explain the strange holes. And it's got nothing to do furry American rodents.

According to Peter, some of the older trees in the park, planted well over a century ago, are starting to show signs of dieback and the holes are part of a plan to save them from a slow death.

Surprisingly, it's not a lack of water from the recent drought that's made their canopy look so sick. According to Peter, "they are actually slowly suffocating due to soil compaction".

"They've been loved to death - think how many picnics and little feet have run over this park in the last 100-plus years since they were planted," says Peter. "Penetrometer readings of the soil indicate under some of the more mature trees, compaction is five times what it should be for a healthy tree. Without oxygen, this compaction will eventually kill the tree."

As part of his plan to revitalise the trees, with support from the local council, Peter has dug a series of 10-centimetre auger holes under the dripline of stressed trees and packed it with coarse sand, "creating a whole lot of chimneys for the air to get back in underground".

He has also treated the soil with a special mixture of mycorrhiza fungi and a bacteria, both selected to nourish the tree.

On the day I visited the park, Milena Ponce and Camila Perez, two Chilean backpackers stranded in Australia due to COVID, were helping Peter care for the trees.

"The town has really embraced them and they have scored jobs in the local bakery, cleaning at the old folk's home and also volunteering with community projects like this one," explains Peter, who along with his wife have generously allowed them to bunk down in their Braidwood house.

Although they miss their families in South America, the two Chileans are smitten with their temporary home.

"We absolutely love it," says Milena while helping Camila spread mulch over an area of the park still pock-marked with the 'gopher holes'.

According to Peter, when they can eventually fly back to Chile the two girls are hoping to use their newly acquired skills to provide a new lease of life to some old street trees in their hometown of Santiago.

"It is a problem worldwide, wherever there is a well-loved street or park tree, it is probably suffering from compaction," explains Peter. "It's definitely the case for some trees in older parts of Canberra."

It seems the white variant of Paterson's Curse isn't as rare as your columnist first thought.

Many readers have reported spotting the colour-challenged flowers of the weed on many of Canberra's hills. Andrea Loos noticed "one lonely little bunch of white amongst all the purple in Duffy" while Bryan Umback reports "white flowers dotted through the patches of purple on Mt Taylor", adding "the bees love them too".

Meanwhile Peter Freer of Lyons reports that back in the 1960s, when a primary school student at Ungarie Central School near West Wyalong in NSW, "we had a lot of Paterson's Curse in the district and we transplanted every white-flowering plant we found to a garden at the school".

"They made quite a show," recalls Peter, "but they didn't breed true." Perhaps the white flowers are a recessive gene, he suggests.

This column's recent feature on Ian Hoskins' Rivers: the lifeblood of Australia (October 10) resulted in a bulging mailbag about our local waterways.

None more provocative than a missive from Russell Wenholz of Holt who argues it should be the Queanbeyan River flowing through the ACT, not the Molonglo River. "I've always been of the opinion that rather than the Queanbeyan River joining the Molonglo, it is the Molonglo joining the Queanbeyan," he controversially attests.

Russell also reports that while at primary school in the 1940s, his big sister learnt the geography of NSW via the location of river towns. "She learned off-pat that it was Murwillumbah on the Tweed, Grafton on the Clarence, Kempsey on the Macleay, Taree on the Manning, Newcastle on the Hunter and Nowra on the Shoalhaven," explains Russell. "Not sure why Batemans Bay on the Clyde never got a mention."

Talking of south coast rivers, John Smithers of Civic asks why the Deua River changes name to the Moruya River for its last few menadering kilmetres. "Other south coast rivers like the Bega, Clyde and Shoalhaven keep their names all the way to the ocean."

Good question.

Clue: They built the hotel for the train but it never arrived!

Degree of difficulty: Medium

Last week: Congratulations to David Nott of Ainslie who was first to correctly identify the location of last week's photo as a block of concrete in Suttor Street in Ainslie. No one was able to confirm its purpose although Steve Dyer, who first alerted this column to the concrete oddity, reckons it looks as if it was ''left behind from some project, long forgotten". "With the steel loop on top, it could have even been a tie-down used to secure objects during high winds such as light aircraft." Someone must know.

How to enter: Email your guess along with your name and suburb to timtheyowieman@bigpond.com. The first email sent after 10am, Saturday October 24, 2020, wins a double pass to Dendy, the Home of Quality Cinema.

Over the last 30 years Rob May of Jerrabomberra reports "over 100 species of birds" have visited his backyard including this friendly female Satin bowerbird. "She first went to the barbecue and picked up a slice of sausage," reveals Rob, adding "then she put her head in my wife's coffee cup, and when the sun reflected off my glasses she pecked first at my ear then the glasses." The brazen bird certainly didn't adhere to the message on Rob's T-shirt which warns: "I'm retired, Move around me".

On a recent walk through Molonglo Gorge, Wynette and Peter Neil were surprised to see this stone face looking back at them. Has anyone else has noticed it?

CONTACT TIM: Email: timtheyowieman@bigpond.com or Twitter: @TimYowie or write c/- The Canberra Times, 9 Pirie St, Fyshwick