I live in the south-western suburbs of Norwich and I’m very fortunate to have plenty of tree-lined streets with grass verges near home. As a consequence, I often find interesting fungi on my walks, sometimes just on a trip to the local shops.

Here are five recent finds.

Ganoderma resinaceum

Last summer some large objects appeared on a grass verge not far from home. With a few added toppings they could easily have been family-sized thick-crust pizzas.

Ganoderma resinaceum

The objects were fruitbodies of a large bracket fungus, Ganoderma resinaceum, which is parasitic on broadleaved trees, especially oaks and Beech. The fungus was growing on the remains of a Red Oak (Quercus rubra) that had toppled over in a gale several years ago. It had presumably started to eat the tree while it was alive and then continued to digest its remains.

Like its close relatives Southern Bracket (Ganoderma adspersum), Artist’s Bracket (Ganoderma applanatum) and Lacquered Bracket (Ganoderma lucidum) it can grow at the base of tree trunks. However, I’ve only seen it growing on the ground, feeding on the remains of tree roots.

I found another Ganoderma resinaceum this summer on a verge south-west of Norwich, growing on another subterranean oak root. Over the weeks I watched it grow in size from small bread roll to medium loaf but it didn’t reach pizza size, presumably because it had a more limited food supply. Similarly, my local specimens were much smaller this summer, suggesting that the remnants of the Red Oak are dwindling.

Ganoderma resinaceum

Although Ganoderma resinaceum can resemble a pizza, the resemblance ends there. The fungus has a spicy smell but apparently tastes bitter and is far too tough to be edible.

Ganoderma comes from the Greek words Ganos and derma and means ‘shining skin’. (The wet cap of Lacquered Bracket, Ganoderma lucidum, is the finest example of this.)

The specific name resinaceum means ‘resinous’. The fungus has a hard resinous coating which will melt when set alight. I haven’t tried this yet; next year, perhaps.

Mealy Domecap, Tricholomella constricta

Tricholomella constricta – Mealy Domecap. Photo: Vanna Bartlett.

Last October, while walking home from the shops, I found some bright white fungi growing on a road verge. They completely puzzled me but Yvonne from the Norfolk Fungus Study Group came to the rescue and identified them as Mealy Domecap, Tricholomella contricta.

The species has also been seen at Whitlingham Lane in Norwich and in the grounds of the University of East Anglia. It appears to favour road verges where dogs urinate (note 1). Knowing this, James Emerson searched likely places in the north of Norwich and soon found the fungus in a spot in New Catton.

Now that I’m familiar with this fungus, it’s easy to recognise. It has a bright white cap, white notched-adnexed gills and a rooting, tapered white stem with a small ring. The fruitbodies smell farinaceous (floury) and are quite robust. Each one can last for a week or two, even in rainy weather.

Vanna found me some more specimens this year, growing on another grass verge in Norwich, in a spot popular with dog walkers.

Tricholomella constricta

Andy Overall found the fungus growing in Holland Park in London in 2011 (note 1).

Ascot Hat, Hortiboletus bubalinus

Ascot Hat, Hortiboletus bubalinus

At the time of writing the Ascot Hat, Hortiboletus bubalinus, has only been seen in Norfolk four times, all in Norwich. Last autumn James Emerson found the first one not far from the city centre, followed a month later by a second sighting made at the University of East Anglia by Ian Senior.

This year I’ve followed up with the third and fourth sightings, from a road verge under Common Limes, and under pine trees in my local cemetery.

Hortiboletus bubalinus is a handsome fungus but is very easy to miss when growing on a grass verge, where its cap (in various shades of pinkish-, yellowish- or reddish-brown or dull apricot) blends into the background.

But if you take a closer look it is an exquisite fungus. Its pores bruise blue when handled, like several other species of bolete and if you cut it open the cap is reddish-brown on top with a pink layer, before staining light blue further down. The colour scheme has been described as being like “sunrise over the sea” (note 2).

“Sunrise over the sea”. Cut open: Hortiboletus bubalinus

Hortiboletus bubalinus was only described in 1991. It was originally known as Boletus bubalinus and became Xerocomus bubalinus in 1993. It was transferred to Hortiboletus in 2015. It appears to be quite new in Britain and was first recorded near Ascot. The Guardian asked for suggestions for an English name back in June 2011 and the English name is now Ascot Hat, which makes more sense when you know about its origin in Britain.

Ganoderma resinaceum is a parasite and Mealy Domecap is presumably a saprobe (eating dead organic matter). Ascot Hat has a symbiotic relationship with trees, helping them take up water and minerals in exchange for carbon from the tree.

It appears to form mycorrhizal relationships with a range of trees, including limes (Tilia), poplars (Populus), Beech (Fagus), birch (Betula), spruce (Picea) and Hornbeam (Carpinus). One of my specimens was growing with Common Lime (Tilia x europaea) and  the other near Scots Pine (Pinus sylvestris).

Hortiboletus bubalinus is edible but I haven’t tried it and probably won’t, given its apparent scarcity in Norfolk. I returned my specimens so that they could continue to release their spores.

Warty Cavalier, Melanoleuca verrucipes

Warty Cavalier, Melanoleuca verrucipes

At the beginning of October I found Warty Cavaliers (Melanoleuca verrucipes) in woodland at the end of my local park. At first I thought the dark marks on the stems was just where soil had splashed upwards in the rain. I took one home to identify.

This was just the fourth record for Norfolk. Warty Cavaliers like to grow on woodchip and this had been spread along the path through the wood, spilling off into the woodland where the fungi were growing. Melanoleuca verrucipes is a saprobe and its favourite meal is wood chip mulch. It was first recorded in Britain in 2000 and is probably an introduction (note 3).

The genus name Melanoleuca comes from the Ancient Greek melas (black) and leucos (white) and other fungi in this genus (Cavaliers in English) have a dark top to the cap and contrasting white gills. Warty Cavalier looks rather different, making it quite easy to identify once you know where to look. Verrucipes means ‘with warty foot’ and refers to the stem.

Under the microscope, Melanoleuca verrucipes has rather nice urticoid cheilocystidia. I explain more in note 4 below.

Warty Cavalier, Melanoleuca verrucipes – its urticoid cheilocystidia.

The Warty Knight may be edible but is likely to be “nothing special“. I wouldn’t bother.

The First Nature website has more photographs of Warty Cavalier, including the spores.

Blushing Rosette, Abortiporus biennis

My fifth fungus is Blushing Rosette, Abortiporus biennis.

I was very puzzled when I first saw this fungus, growing on the underground remains of another tree (possibly another Red Oak). It looked like it might turn into a bracket of some kind, but which species?

I posted a photograph on the Norfolk Fungus Study Group Facebook page and Neil Mahler came up with an identification: Blushing Rosette, Abortiporus biennis.

Blushing Rosette, Abortiporus biennis. 11th October 2023.

Rosette, what rosette?

I made a return visit at the end of the month and it was very much in evidence.

Twenty days later: Blushing Rosette, Abortiporus biennis. 31st October 2023.

But the prize for the wackiest specimen of Blushing Rosette must go to a huge outpouring of growth on a fallen tree trunk in Earlham Park in Norwich, which Vanna found earlier this month. It resembles a series of volcanic cones rather than a fungus.

Blushing Rosette, Abortiporus biennis. Earlham Park, Norwich, November 2023.

Abortiporus biennis is another saprobic fungus, feeding on the dead remains of broadleaf tree roots and stumps.

If you look at the underside of the rosette you will see a network of white or buff angular pores.

The genus name, Abortiporus, comes from the Latin Abortus– meaning arrested development (of an organism), and –porus, derived from ancient Greek and meaning a pore. The specific name biennis is misleading. Biennis means biennial but the fruitbodies are annual. The fungus isn’t edible and you might break your teeth if you tried to eat it.

The First Nature website has more photographs of Blushing Rosette, including the spores.

Notes

Note 1 – One Norfolk record was from a cat latrine and another specimen was growing in Earlham Cemetery, possibly on an animal latrine (although some people insist on ignoring the “No Dogs” signs).

In his article “Urban Fungi – interesting fungi from parks and gardens of West London” (Field Mycology Vol. 14 pp98 – 102, 2011) Andy Overall notes “This species is known to favour urine-enriched sites …more probably the common factor is merely the presence of dogs.”

Note 2 – A post on Reddit by “the frisker” mentions the “Sunrise over the sea” nickname and gives “Aurora Bolete” as a Scandinavian name for Hortiboletus bubalinus. “Sunrise above the sea” is mentioned in “Fungi of Temperate Europe” (page 786) by Thomas Læssøe and Jens H Petersen (Princeton University Press, 2019).

Note 3 – Geoffrey Kibby (2020), “Mushrooms and Toadstools of Britain & Europe – Volume 2, Agarics – part 1”. (One of four superb volumes for identifying British Basidiomycete fungi.)

Note 4 – Cystidia are relatively large cells found in various places on the fruitbody of a Basidiomycete fungus. They vary in shape between species and this can be key to the microscopic identification of fungi.

Cheilocystidia are cells that project from the edge of the gill of a fungus fruitbody. “Urticoid” means shaped like a stinging-nettle hair (with a long straight pointed section and a swollen base).