Arched Earthstar, Geastrum fornicatum

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Arched Earthstars. Geastrum fornicatum

A couple of Arched Earthstars. Geastrum fornicatum, 4th February 2024.

I’ve seen quite a few different earthstars and I’ve written about some of them on this blog – the Vaulted Earthstar (Geastrum britannicum), Collared Earthstar (Geastrum triplex) and the very localised coastal Dwarf and Tiny Earthstars (Geastrum schmidelii and Geastrum minimum). All are basiodiomycete fungi and members of the family Geastraceae.

Arched Earthstars in Norfolk

One species I hadn’t seen until recently was the Arched Earthstar, Geastrum fornicatum. But fungi can be like buses – you wait ages to see one and then two come along at once. Since the start of this month I’ve seen Arched Earthstars in two different places (note 2).

Arched Earthstars aren’t common in Norfolk and up until the end of 2023 were only known from 14 different sites.

My first sighting was on 4th February. Returning from a trip to a site just outside Norwich with our friends Sarah and Ian, Sarah stopped the car by our Vaulted Earthstar (Geastrum britannicum) site. I spotted an earthstar on the road verge and Vanna was about to say ‘Arched Earthstar’ but Ian got there a couple of seconds earlier. We then looked under the nearby Yew tree and Vanna counted 31 earthstars. They were all Arched Earthstars, Geastrum fornicatum, and we didn’t see any Geastrum britannicum.

Six days later Vanna and I cycled down to South Norfolk. It was a successful day – we had found a new site for Sandy Stiltball (Battarrea phalloides) on a road verge on our way south. We had lunch in a churchyard and found a couple of dozen Arched Earthstars beneath a Yew tree. There were several Yews but just one with earthstars underneath.

Identifying Arched Earthstars

The genus name for earthstars, Geastrum, comes from geo meaning ‘earth’ and aster meaning ‘star’. The fruitbody consists of an inner and outer wall (peridium): the inner peridium is the spore sac and the outer peridium splits to form rays in a star shape (note 2).

The specific name for the Arched Earthstar, fornicatum, means ‘arched’. Its red-brown rays are upright and push the spore sac upwards, giving the earthstar an upright (arched) appearance. The spore sac has a swelling on its underside, known as the apophysis.

The rays of an Arched Earthstar are attached to a basal cup of mycelium, a feature shared with the Vaulted Earthstar (Geastrum britannicum) and Rayed Earthstar (Geastrum quadrifidum) (note 3). Arched Earthstars are 4 – 8cm across when the fruitbody is expanded, with four to five rays. The peristome, the hole in the top of the spore sac, is not delimited, in contrast to that of G. britannicum (note 4).

If you find a group of earthstars, it is worth examining as many as possible, especially when they are old and weathered. The spore sac on the one pictured below is a bit damaged but its basal cup is intact; other fruitbodies had a spore sac in better condition but had become detached from their basal cups.

Arched Earthstar. Geastrum fornicatum

Arched Earthstar. Geastrum fornicatum

Distribution

Geastrum fornicatum is found in southern England and Wales and there is a single record on the NBN Atlas for Ireland. it is widespread elsewhere in Europe but uncommon (note 5). It also occurs in the United States, growing under Monterey Cypress in California and in Australia, “in litter under trees in dry woodlands and mallee scrub”.

‘Reminiscent of ballet dancers’

In the United States Geastrum fornicatum is sometimes known as the Acrobatic Earthstar and Pat O’Reilly on his First Nature website notes how “these earthstars do have silhouettes reminiscent of ballet dancers”.

In 1799 the English naturalist James Sowerby (1757 – 1822) wrote a book entitled “Coloured Figures of English Fungi or Mushrooms“. In it, he described how Geastrum fornicatum (then known as Lycoperdon fornicatum) resembled the human figure:

“So strange a vegetable has surprised many; and in the year 1695 it was published under the name of Fungus Anthropomorphus, and figured with human faces on the head. It is at first roundish; in ripening the head bursts through the two coats or wrappers; the inner wrapper, detaching itself from the outer, becomes inverted, connected only by the edges; the coats most constantly split into four parts.”

There are good photos of Geastrum fornicatum on the First Nature website.

If you’re interested in identifying more earthstars, the guide “How to identify British earthstars” by Phil Gates on the Discover Wildlife website describes some of the other species.

I also thoroughly recommend “Mushrooms and Toadstools of Britain & Europe – Volume 1” (2017) by Geoffrey Kibby, which has two pages of earthstar illustrations and shows the three species which have basal cups side by side. Kibby describes the habitat of Arched Earthstars as being on soil under broadleaved trees.

Finally, we found the Vaulted Earthstars we’d missed on 4th February. Last Saturday we cycled past our Vaulted Earthstar (Geastrum britannicum) site and looked a little further along the road under a different Yew tree. We found a few more Arched Earthstars and, happily, at least half a dozen Vaulted Earthstars too (note 6).

Vaulted Earthstar, Geastrum britannicum

One of the Vaulted Earthstars, Geastrum britannicum. 17th February 2024.

Notes

Note 1 – The phenomenon of buses arriving together is explored on Jason Cole’s blog and in this New Scientist article from 2009.

Note 2 – It is estimated that there are up to 120 species of Geastrum throughout the world.

Note 3 – I haven’t seen the Rayed Earthstar (Geastrum quadrifidum). There are two records for Norfolk, but from the days before the Vaulted Earthstar (Geastrum britannicum) was recognised as a separate species. Rayed Earthstar is small (just 1.3 – 3.7cm across), rather uncommon and is usually found under Beech trees (Fagus sylvatica) on calcareous soils in southern England.

Note 4 – There is a good diagram of what a delimited peristome looks like in the 2009 publication “The distribution and identification of earthstars (Fungi: Geastraceae) in Norfolk” by Tony Leech, Trevor Dove & Jonathan Revett. See figure 4. (Note that this paper was written before Geastrum britannicum was recognised as a separate species.)

Note 5 – Geastrum fornicatum is featured on page 1251 in Volume 2 of Laessoe and Petersen’s two volume “Fungi of Temperate Europe”. They describe it as “widespread in the nemoral zones, very rare”. (“Nemoral” refers to the vegetation zone of temperate forests in Eurasia.)

Note 6 – I also checked the spores from the Arched and Vaulted Earthstars I found on each occasion. Both have globose, warted spores but those of Arched Earthstar (Geastrum fornicatum) are 3.5 – 4.2 µm across and those of the Vaulted Earthstar (G. britannicum) are smaller, 3 – 3.8 µm across. Both measurements exclude the warts.

Basil Thyme, Clinopodium acinos

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In July 2023 four of us visited the Norfolk Brecks to look for insects and plants. We found several Breckland specialities but the best plant we found was Basil Thyme, Clinopodium acinos, which was growing in gravel at the side of a forestry track. It was a new species for me.

Basil Thyme

Basil Thyme, Clinopodium acinos

Basil Thyme, Clinopodium acinos. Norfolk Brecks, 30th July 2023.

Basil Thyme, Clinopodium acinos, is a member of the Mint family, Lamiaceae (note 1). It’s a pretty annual or short-lived perennial plant with stems to 25cm (10 inches) tall, though often much less. Its leaves are oval-elliptical and scented (note 2). It has whorls of flowers from May to September, which are normally violet with a white horseshoe-shaped mark at the centre.

Basil Thyme, Clinopodium acinos

Close up: Basil Thyme, Clinopodium acinos. Norfolk Brecks, 30th July 2023.

Basil Thyme grows on disturbed soils with not too much competition, where it can spread by seed.

Basil Thyme is a native plant in Britain and the Channel Islands. It’s usually found on calcareous soils, in dry grassland, on rocky ground and in arable fields. It also occurs as a casual on waste ground, in quarries and pits, on banks and beside roads and railways. In East Anglia Mike Crewe describes it as frequent on chalky soils in Breckland but scarce and declining elsewhere. The BSBI Species Account for Basil Thyme recommends that management of its habitat should aim for a short sward by the end of the growing season. Depending on the habitat, this can be achieved by grazing with sheep, cutting and removing the arisings, grazing by feral rabbits, or sometimes a mixture of all three.

Basil Thyme has declined substantially since the 1960s as more efficient methods of weed control on arable land have taken their toll. There is only one recent record from Scotland, from a golf course near Elgin in Moray (but see note 3). In Surrey, the plant has been recorded at Banstead Downs. In Leicestershire and Rutland the plant is now restricted to sparsely vegetated limestone quarries. In Wales, one of the places Basil Thyme grows is on the Great Orme, as pictured on the UK Wildflowers website (note 3).

In Ireland Basil Thyme is a neophyte which grows in sandy and gravelly places and some of these have been damaged or destroyed by gravel extraction.

Outside the British Isles, Clinopodium acinos is native in most European countries (but not Portugal) and its range continues east into Turkey, Iran and western Siberia. It is extinct in Morocco but introduced into Kazakhstan, parts of eastern Siberia, New Zealand’s South Island and parts of the United States (note 4).

If you can find a supplier, Basil Thyme makes a good garden plant but it doesn’t like competition from other plants and hates shade. It needs well drained, alkaline soil in full sun. It is very hardy and tolerates temperatures down to at least -15°C. Plants are short-lived but should self seed. The Useful Temperate Plants website says it makes a good, temporary ground cover. If you grow it, you could try using it as a herb for flavouring food. The Useful Temperate Plants website also lists some medicinal uses. The Celtic Wildflowers website lists pot grown plants, but these were out of stock at the time of writing.

Basil Thyme seed can be sown in early spring in a cold frame. Seedlings should be pricked out and potted up individually once they are large enough to handle and then planted out during the summer. Seed can also be sown direct in April or May. Existing plants can be divided by basal cuttings in late spring.

Also Available In White

Although my first photos in this blog post are of Basil Thyme with typical violet flowers, the first plants we found had white flowers.

Basil Thyme, Clinopodium acinos

Basil Thyme, Clinopodium acinos, with white flowers. Norfolk Brecks, 30th July 2023.

Basil Thyme Case-Bearer

Basil Thyme is the food plant of a rare moth, the Basil Thyme Case-bearer, Coleophora tricolor. The moth lays her eggs in August on Basil Thyme flowers and the larva spins a silk case over a single calyx of Basil Thyme and feeds within its protection. It overwinters on nearby grasses then makes a new case from hollowed out grass leaf-blades in late spring. Here it pupates and adult moths emerge in July and August.

The moth was first recorded in Norfolk in 1899 but after 1914 there were no records for over fifty years. The Norfolk Moths and Suffolk Moths websites show the current distribution in Norfolk and Suffolk, but understandably they keep exact locations of records confidential. There are photos of the moth on the Norfolk Moths website and in the Butterfly Conservation factsheet for the species. Norfolk and Suffolk are the only locations for the moth in the British Isles but it has been recorded in France and Greece. The moth can be attracted to light and flies on sunny days but the easiest way to find it is to search for the larval cases in autumn.

Two Other Finds

We didn’t find the moths but it was still a good day for insects. Highlights included our first Median Wasps (Dolichovespula media) and the striking tachinid fly, Ectophasia crassipennis. Both species are moving their ranges north as the climate warms.

The first British Median Wasps were recorded in 1980 in East Sussex and by 1995 the species had spread north as far as Cumbria and County Durham. The species has now reached Scotland. It is our second largest species of social wasp. (The Hornet, Vespa crabro, is the largest.)

Median Wasp, Dolichovespula media

Median Wasp, Dolichovespula media, on Snowberry flowers. Norfolk Brecks, 30th July 2023.

Ectophasia crassipennis is common in the Channel Islands. In 2019 it was recorded from several sites on the south and east coast of England. 2023 was the first year with records from the Norfolk Brecks.

Ectophasia crassipennis

A male Ectophasia crassipennis on a Wild Carrot (Daucus carota) flower. Norfolk Brecks, 30th July 2023. We had seen a female of the same species nearby four days earlier.

Notes

Note 1 – The BSBI uses the name Clinopodium acinos, as does Clive Stace in his New Flora (“New Flora of the British Isles“ by Clive Stace, Fourth Edition, 2019). Prior to a revision of the Lamiaceae in 2004 the plant was known as Acinos arvensis. The older name for the Lamiaceae, which I learnt as a child and used at university in the early 1980s, was the Labiatae.

Note 2 – The BSBI species account says the leaves are “faintly aromatic“, while Mike Crew says they are “strongly aromatic“. (The pungency will depend on the weather and perhaps growing conditions, as well as the observer’s sense of smell.)

Note 3 – https://plantnetwork.org/wordpress/wp-content/uploads/4714/clinacin.pdf lists the number of native sites for Basil Thyme in each county in Scotland, England and Wales. The document is undated. The only Scottish site listed is in East Lothian, rather than Moray. Overall, Norfolk leads with 28 sites, with Wiltshire next with 16 sites. There are seven sites listed for Suffolk, where Basil Thyme is a Suffolk Biodiversity Information Service priority species.

Note 4 – For the United States, Plants of the World Online lists New York, Vermont and Wisconsin but the Native Plant Trust lists Connecticut, Maine, Massachusetts and Vermont in New England. A BONAP (Biota of North America Program) map on the Native Plant Trust website shows a wider distribution for Clinopodium acinos in the United States.

Five Fungi from the Lanes of Norfolk

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Last month I looked at five fungi from my local streets in Norwich. But I’ve seen plenty more fungi by bike and here is a selection of five more from this summer and autumn, all seen within ten miles of home.

Ringed Milkcap, Lactarius circellatus

In early August Ringed Milkcaps, Lactarius circellatus, appeared in their usual spot under Hornbeam trees in Earlham Cemetery.

Ringed Milkcaps were found in Norfolk Wildlife Trust’s Ashwellthorpe Lower Wood in the 1990s so I decided to cycle out to re-find them. I succeeded in my quest.

Better still, I found Ringed Milkcaps at a new site, growing under Common Hornbeams on a road verge on my way out to the wood.

Ringed Milkcap, Lactarius circellatus

Ringed Milkcap, Lactarius circellatus. Earlham Cemetery, Norwich, 8th August 2023.

Ringed Milkcaps have depressed caps with grey-brown rings, and the fairly crowded gills start pale cream and become pinkish buff with age. They smell fruity and their milk is rather abundant and white, turning slowly yellowish. The milk tastes acrid and leaves a bitter taste at the back of the tongue (note 1). The fungus isn’t considered edible.

Milkcaps form mycorrhizal relationships with trees, providing water and minerals for the tree in exchange for carbon manufactured by photosynthesis.

Lactarius circellatus forms a mycorrhizal relationship with Common Hornbeam, Carpinus betulus (note 2).

Common Hornbeam is native in south-east England, but has been widely planted elsewhere in the British Isles. Lactarius circellatus is not particularly common, with only nine records in Norfolk to the end of 2022. Ashwellthorpe Lower Wood is full of Common Hornbeams but in August I only found Ringed Milkcap in a couple of places. Similarly, although there were ten (planted) Common Hornbeam trees on the verge, I only found the fungi underneath one tree.

Ringed Milkcap, Lactarius circellatus

Ringed Milkcap, Lactarius circellatus, under a Common Hornbeam on a road verge. 10th August 2023.

Iodine Bolete, Hemileccinum impolitum

We were cycling home from a trip to South Norfolk at the end of September when Vanna spotted a large bolete growing on a road verge. We stopped to take a look and found two more, including a smaller, younger specimen which we took home to identify (note 3). We had found our first Iodine Boletes, Hemileccinum impolitum (formerly Boletus impolitus).

Iodine Boletes form a mycorrhizal relationship with a variety of broadleaved trees – ours were near an English oak (Quercus robur).

Iodine Bolete, Hemileccinum impolitum

Iodine Bolete, Hemileccinum impolitum. 30th September 2023.

Unlike many of its relatives, the Iodine Bolete doesn’t change colour when cut or bruised. The cap is a felty, greyish beige and the pores are lemon yellow. (“Impolitum” refers to the rustic, unfinished or unpolished appearance of the cap.)

Cutting open the fruitbody reveals beautiful lemon yellow flesh. There is a distinctive smell of iodoform (hospital disinfectant) at the base of the stem, which gives the fungus its English name.

Iodine Bolete, Hemileccinum impolitum

Iodine Bolete, Hemileccinum impolitum. 30th September 2023.

Iodine Bolete is not a common fungus and there are only 15 records in Norfolk to the end of 2022. As it isn’t common, the First Nature website rightly recommends that this “edible although hardly delectable” fungus “should not be picked for the pot” and I would normally follow this advice. However, I’d already picked my specimen for identification so I decided to fry the remains in butter and thoroughly enjoyed both the taste and texture.

Flame Shield, Pluteus aurantiorugosus

Shield fungi (whose generic name Pluteus means “shield, protective fence or screen”) grow on decaying wood and come in a variety of colours.

The Deer Shield (Pluteus cervinus) has a brown cap, the Willow Shield (P. salicinus) has a grey cap and the cap of the Yellow Shield (P. chrysophlebius) is a bright greenish-yellow or golden yellow. But it’s hard to beat a Flame Shield, Pluteus aurantiorugosus, with its stunning flame orange cap. Underneath the cap, the gills start off white and become pink at maturity, and the spores are brownish-pink. The edges of the cap are usually yellowish-orange.

Flame Shield, Pluteus aurantiorugosus

Flame Shield, Pluteus aurantiorugosus. 24th October 2023.

I wasn’t expecting to find a Flame Shield at ground level on a road verge but sharp-eyed Vanna spotted a glint of orange as we cycled past, and there it was. I’m used to seeing shields on substantial logs or dead tree branches but this one appeared to be growing on the soil. It must have been attached to a piece of rotting wood beneath the surface.

Up to the end of 2022 there were only eight records of Flame Shield in Norfolk but 2023 seems to have been a good year for them and I’ve seen the species three times since the end of September.

The Flame Shield is in the family Pluteaceae, as is the…

Stubble Rosegill, Volvopluteus gloiocephalus

Stubble Rosegills, Volvopluteus gloiocephalus, sometimes grow on stubble fields after harvest, feeding on the remains of the crop. They also grow on road verges and this is where I usually find them (note 4).

Last year we saw most of our Stubble Rosegills on one day in November, on a cycle ride to Suffolk. This year they were abundant in early October.

The Stubble Rosegill is a very distinctive fungus and in its prime it is a great beauty. Young specimens are white and soon become pale grey, ageing to the colour of milky coffee. The cap is sticky when moist but silkily tactile when dry. The gills are crowded, starting white and becoming pink.

A Stubble Rosegill’s stem is often hidden in grass but if you gently part the leaves there is a fleshy bag-like volva at the base of the stem, as in species of Amanita (such as Fly Agaric and Deathcap). Be careful when you move the grass leaves, though. The Stubble Rosegill  looks robust but it’s actually rather flimsy and the grass may all that is keeping the fungus upright.

The Stubble Rosegill is quite a common fungus and there are 221 records from Norfolk up to the end of 2022.

Here is a sequence of the development of Stubble Rosegills, in pictures:

Stubble Rosegill, Volvopluteus gloiocephalus

A young Stubble Rosegill, Volvopluteus gloiocephalus. Growing on straw, 8th October 2023.

Stubble Rosegill, Volvopluteus gloiocephalus

A Stubble Rosegill in its prime, showing the volva at the base of the stem. 13th November 2022.

Stubble Rosegill, Volvopluteus gloiocephalus

An older Stubble Rosegill, Volvopluteus gloiocephalus. 13th November 2022.

The “volvo” in the generic name Volvopluteus refers to the volva at the base of the stem (note 5). The specific name gloiocephalus comes from the Greek words gloio (glue) and cephalus (head), a reference to the stickiness of the cap when wet. Older books refer to the Stubble Rosegill as Volvariella gloiocephala.

I haven’t tried eating Stubble Rosegills and I don’t pick them because I can identify them in the field but apparently they are edible but not highly rated. There is the danger that, with their volva, an inexperienced forager could mistake them for a toxic Amanita (such as the white form of Deathcap or the Destroying Angel), with fatal consequences (note 6).

Trooping Funnel, Infundibulicybe geotropa

Yesterday was gloriously sunny and quite mild and I went for my first bike ride since late November. The cold weather of the previous week had marked the end of autumn and I didn’t expect to see any fungi, so a group of Trooping Funnels (Infundibulicybe geotropa) was a pleasant surprise.

The Trooping Funnel is one of the few large mushrooms that can endure mild frosts, so specimens can survive right through to late December.

Trooping Funnel, Infundibulicybe geotropa

Trooping Funnel, Infundibulicybe geotropa. 8th December 2023.

Trooping Funnels grow in deciduous and coniferous woodland, especially with Beech and oaks. Mine were in deciduous woodland by the side of the road, growing in a line, but they often form fairy rings, which can persist for many years. One in France measures half a mile across and is estimated to be 800 years old. They are stately fungi with strongly decurrent gills under a conical or bell-shaped cap.

Trooping Funnels, Infundibulicybe geotropa

Trooping through the woods – Trooping Funnels, Infundibulicybe geotropa. 8th December 2023.

An older name for Trooping Funnel was Clitocybe geotropa. Clitocybe means “sloping head” and geotropa means “turn towards the earth”, because the cap margin in young specimens turns downwards. Older caps are more flattened.

The new genus Infundibulicybe was created in 2003.

This is another fungus I haven’t eaten, but it is edible when young (note 7).

Notes

Note 1 – ‘Circellatus‘ means ‘”with circular zones”, referring to the rings on the cap.

The genus name, Lactarius, is derived from the Latin “lac“, meaning milk. The “milk” (also known as “latex”) is a fluid produced when the fungus is damaged and its function is probably to clog up the mouthparts of insects and other tiny animals that try to eat the milkcap. Anecdotal evidence supports this theory – I find that milkcaps’ close relatives the Brittlegills (Russula spp) have usually been nibbled by slugs, while milkcaps remain intact.

Taste is a useful tool in the identification of milkcaps. If you dab a bit of milk on your tongue, it can be mild or acrid (hot) or bitter. (The idea is not to actually eat the fungus – you spit out any residue and, if it is hot or bitter, can rinse out your mouth with water.) The milk’s colour is useful too, and whether it changes colour after several minutes – best seen when a spot of milk is dabbed on a paper tissue. Species also differ in their milk’s consistency (from watery to thick) and how abundantly it is produced.

For milkcap identification I use “British Milkcaps: Lactarius and Lactifluus” (2016) and “Mushrooms and Toadstools of Britain & Europe – Volume 1” (2017), both by Geoffrey Kibby. “The Genus Lactarius” by Jacob Heilman-Clausen, Annemieke Verbeken and Jan Vesterholt (1998) is also well worth a look.

Note 2 – As you’ll know from reading some of my other blog posts, such as the one on Rooting Bolete (August 2023), it is usually necessary to cut open a bolete to look at its internal colour and whether it changes colour on cutting. I do this on the spot for larger specimens but sometimes I take smaller specimens home, where I have time to observe any changes and the necessary reference books.

Note 3 – The Picture Mushroom website (and app) and Mycota of Alaska website say that Lactarius circellatus grows in moss under Mountain Hemlock (Tsuga mertensiana) and spruce (Picea). But in Britain, it is only found with Common Hornbeam.

Note 4 – The Stubble Rosegill is usually found on the remains of a grain crop but it will also grow on the leftovers of other food crops, such as cabbages.

Note 5 – In contrast the name of the car, “Volvo”, comes from Latin for “I roll”.)

Note 6 – I like this excerpt from an article about mushroom hunting on Vancouver Island in Canada:

‘“Is that one edible?” someone asks.

“Well sure, it’s edible. But it’s not very good,” he says. “It’s funny how many people ask that. Almost all mushrooms are edible, but so are most birds. You don’t hear birders asking if all the birds they spot are edible.” 

There’s an Eastern European quote, borrowed by author Terry Pratchett, that comes to mind: All mushrooms are edible; however, some are edible only once.’

Note 7 – In contrast the Ivory Funnel, also known appropriately as the Fool’s Funnel (Clitocybe rivulosa), is very toxic. It tends to grow in short turf on lawns.