Yellow Bird’s-nest, Hypopitys monotropa

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If you go down to the woods today I can guarantee that you won’t see Yellow Bird’s-nest, Hypopitys monotropa. But go back in summer and, if you’re lucky and it’s the right kind of woodland, you might see this curious and subtly beautiful flower.

Yellow Bird's-nest, Hypopitys monotropa

Yellow Bird’s-nest, Hypopitys monotropa. Speyside, June 2024.

Yellow Bird’s-nest swaps its names

Scientific names of plants have a habit of changing and recent DNA studies have caused a swap around of Yellow Bird’s-nest’s generic and specific names from Monotropa hypopitys to Hypopitys monotropa. Yellow Bird’s-nest has switched families too. Older floras list it as a member of the Monotropaceae or Pyrolaceae (along with Wintergreens) but all these are now considered to be members of the Ericaceae, the Heather family (note 1).

I first saw Yellow Bird’s-nest growing under Beeches in Thetford Forest in July 2021. The Beech leaves cut out bright the summer sunlight from the woodland floor and the plant’s flowers looked eerie and mysterious in the gloom.

Yellow Bird's-nest, Hypopitys monotropa

Yellow Bird’s-nest, Hypopitys monotropa. Thetford Forest, July 2021.

Food from fungi

Yellow Bird’s-nest is a rather strange plant.

It is a perennial with no leaves or true stem and it doesn’t manufacture its own food by photosynthesis, but it isn’t a direct parasite on plants either, unlike the Broomrapes, Orobanche (note 2).

Yellow Bird’s-nest was once thought to be saprophytic, obtaining its nutrients from decaying organic matter. But Hypopitys monotropa is actually a myco-heterotroph, a parasite that obtains its food from a fungal partner, various species of fungus in the genus Tricholoma. Tricholoma species (Knights) form mycorrhizal relationships with their host trees, trading nutrients and water for the sugars the tree manufactures by photosynthesis. Yellow Bird’s-nest has need of some of these sugars too, so it is an indirect parasite on the trees, via its fungal host.

In 2004 a study demonstrated that Yellow Bird’s-nest associates with the ectomycorrhizal fungus Tricholoma cingulatum (Girdled Knight) under willow trees (Salix) and with its relative Tricholoma terreum (Grey Knight) under pines (Pinus) (note 3). There are many more species of Tricholoma, associated with other species of trees and presumably Yellow Bird’s-nest parasitises some of these other fungi too.

Grey Knights, Tricholoma terreum

Grey Knight, Tricholoma terreum, under pines at Holme-next-the-Sea, November 2019.

Where to find Yellow Bird’s-nest

Yellow Bird’s-nest flowers from June to August in the British Isles. (The Wild Flower Finder website has a good selection of photographs.)

In Norfolk, I’ve seen Hypopitys monotropa under Beech (Fagus sylvatica) trees in Thetford Forest and beneath pine (Pinus) trees at the back of Holkham Beach. The latter sighting was in the drought and extreme heat of July 2022, which did no favours to the dying, drying flower heads.

Yellow Bird's-nest, Hypopitys monotropa

Yellow Bird’s-nest, Hypopitys monotropa. Under pines at Holkham, frizzled up in the drought, July 2022.

The BSBI Plant Atlas shows the distribution of Hypopitys monotropa in the British Isles. The plant is widely distributed but it becomes increasingly rare towards the north and west. It is absent from the Isle of Man, the Isles of Scilly and the Northern and Western Isles. It suffered substantial losses in the 19th and early 20th centuries and it seems to be declining still.

Yellow Bird’s-nest is not an easy plant to monitor, because it doesn’t necessarily flower every year, and this has probably led to under-recording, especially in Ireland.

In Ireland, Northern Ireland has more than half the records and it grows mainly in County Fermanagh, with isolated sites in County Londonderry and County Antrim. It is listed as rare in the Irish Red Data Book and on the British mainland it is “not quite a Nationally Scarce species“.

There are two subspecies of Hypopitys monotropa in the British Isles (subsp. monotropa and subsp. hypophegea). They differ in chromosome number and some features of the flower. Stace’s Flora (note 1) gives full details, as does the Wild Flower Finder website.

The best places to look for Yellow Bird’s-nest is in the leaf litter of shaded Beech and Hazel on calcareous soils, under pines on more acid soils and in dune slacks with Creeping Willow, Salix repens. The association with Tricholoma fungi is key, though you’ll usually need to visit in autumn to see any fruitbodies.

The other place I’ve seen Yellow Bird’s-nest was near Aviemore, in June 2024. It was growing in mixed woodland with plenty of pines and they were the brightest, freshest specimens I’ve seen. The light was good too, so I took several photographs, including the one at the top of this page (note 4).

Yellow Bird’s-nest flowers apparently smell of honey, so I must take a sniff next time I see some.

Hypopitys monotropa worldwide

Hypopitys monotropa grows in the temperate zone of the Northern Hemisphere and is native throughout Europe, Asia and North America, reaching into Central America. It can flower from April to December, depending on where it grows. 

In North America, Yellow Bird’s-nest flowers from May to October. It is listed as endangered in Florida and threatened in Iowa.

In Britain our plants are yellow but in North America plants that flower in summer have sparsely hairy yellow flowers and those that flower in autumn have densely hairy red flowers. There are some lovely photographs of American plants on the USDA Forest Service website.

In North America Hypopitys monotropa is known as Dutchman’s Pipe and Pinesap. (Another name is False Beech-drops.) “Pinesap” refers to the plant’s habit of growing under pines, as does the generic name: from Latinized Greek hypo-, “under”, and pitys, “pine”.

Notes

Note 1 – I am using the Fourth Edition of Clive Stace’s “New Flora of the British Isles“ (2019), where Hypopitys appears on page 567.

Note 2 – I have written about a couple of species of Broomrape: Ivy Broomrape (Orobanche hederae) in June 2016 and Purple Broomrape (Orobanche purpurea) in January 2016.

Note 3 – See the study by Leake JR, McKendrick SL, Bidartondo M, Read DJ. “Symbiotic germination and development of the myco-heterotroph Monotropa hypopitys in nature and its requirement for locally distributed Tricholoma spp.” New Phytol.  Vol 163(2): pp405-423 (2004).

Note 4 – There is no dot on the map in the BSBI Atlas for Speyside but I have been told that it is a known site for the plant.

Whiskery Milkcap, Lactarius mairei

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Milkcaps (genus Lactarius) are some of my favourite fungi. They have decent sized fruitbodies that come in a range of subtle but beautiful colours, in shades that belong on a rather exclusive paint colour chart. Milkcaps exude “milk” from their gills, the genus name, Lactarius, being derived from the Latin “lac“, meaning milk.

I always love to see a milkcap, and it’s even better when it’s a species I haven’t seen before.

The Whiskery Milkcap, Lactarius mairei, is a very attractive but rather rare fungus. This autumn I’ve been fortunate to see it twice in Norfolk.

First Sighting

My first sighting was a “twitch”, visiting a known site after someone had posted pictures of it on Facebook.

Whiskery Milkcap, Lactarius mairei

Whiskery Milkcap, Lactarius mairei. October 2023. Photo: Chris Lansdell.

The site was on the edge of the Norfolk Brecks by the edge of a minor road bordered by Pedunculate Oak trees (Quercus robur). I learnt about the milkcap in late October last year but the weather was rather wet and windy at the time, so I chose not to cycle the fifty miles from Norwich to visit it. Fortunately my friend Chris had managed to go and took some pictures.

Whiskery Milkcap, Lactarius mairei

Whiskery Milkcap, Lactarius mairei. October 2023. Photo: Chris Lansdell.

I was pleased when the milkcaps reappeared in late September this year in the same spot. The weather was dry and sunny and provided just the right conditions for a bike ride. I found the spot (marked by a rather pungent dog waste bin just a few yards away) and saw the fungi.

The fruitbodies were tiny, only just emerging from the dry ground. The photograph below shows the size of one of the caps, with a dead Ivy leaf for scale. In twitchers’ speak it was a “ticK’ but not the most beautiful or spectacular specimen.

Whiskery Milkcap, Lactarius mairei

Whiskery Milkcap, Lactarius mairei, September 2024.

A Chance Encounter

My second sighting was on Tuesday this week. Vanna and I had gone for a bike ride along the Yare valley west of Norwich and stopped in a churchyard for lunch.

On the way in Vanna found a single woolly pinkish buff cap lying on the grass: it was Lactarius mairei again. There was no sign of the stem.

Whiskery Milkcap, Lactarius mairei

Cap of a Whiskery Milkcap, Lactarius mairei.

I took a sniff of the cap and noticed a delicate, slightly fruity smell. Geoffrey Kibby describes the odour as “acidic-fruity of Pelargonium, to slightly oily” (note 1).

This time I was able to see the underside of the cap and the copious white “milk” that was oozing from the gills.

Whiskery Milkcap, Lactarius mairei

Whiskery Milkcap, Lactarius mairei, underside of cap.

Taste is a useful tool when identifying 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.

So I dabbed a little of the abundant, white milk on my finger and tasted it. I don’t mind heat but this was not only very acrid but left a very nasty taste, difficult to describe but very unpleasant and lingering. Luckily it was lunchtime and a couple of mouthfuls of peanut butter sandwich took the taste away (note 2).

Rare, with oaks

Whiskery Milkcaps form mycorrhizal relationships with oak trees and our specimen was beneath the spreading branches of a large Pedunculate Oak (Quercus robur). The fungus receives sugars from the tree, manufactured from sunlight by photosynthesis and in exchange it grows as an extension of the tree’s root system and provides the oak with water and minerals.

In Britain, Lactarius mairei is mainly found in southern England where oaks grow on calcareous soils. At the time of writing there are five records from Norfolk, from four different sites. The NBN Atlas has 38 records, all but one south of The Wash. The fungus is considered rare in Britain and is scarce in other parts of Europe too, appearing in several countries’ red data books.

The Whiskery Milkcap is usually found in September and October. The species was first found in Morocco and described for science by Georges Jean Louis Malençon in 1939. The specific name, mairei, is a tribute to the French botanist and mycologist René Maire.

I’m glad to have seen it. Next time I hope to see a full sized whole specimen, complete with stem. I might not taste the milk though.

Thanks to Chris Landell for allowing me to use his photographs.

Notes

Note 1 – “British Milkcaps: Lactarius and Lactifluus” (2016) by Geoffrey Kibby.

I also consult “Mushrooms and Toadstools of Britain & Europe – Volume 1” (2017) by Geoffrey Kibby and “The Genus Lactarius” by Jacob Heilman-Clausen, Annemieke Verbeken and Jan Vesterholt (1998) when I want to identify a milkcap.

Note 2 – The “milk” (also known as “latex”) is 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 fungus. 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.

Given my experience of the milk’s taste, if I am reincarnated as a slug I will think twice before eating a Whiskery Milkcap!

Shaggy Bracket, Inonotus hispidus

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The Shaggy Bracket, Inonotus hispidus, is a fungus that produces annual brackets from summer to early autumn on a variety of deciduous trees. I usually see its brackets on Ash trees but they grow on several old Apple trees on our allotment site and the first ones I saw were on Whitebeam trees on a street in Norwich (note 1).

Young and Beautiful

When young and fresh, Inonotus hispidus is a really beautiful fungus, in shades of reddish-orange. Shaggy Bracket oozes liquid as it grows, a phenomenon known as guttation (note 2).

The top of a Shaggy Bracket starts off soft and almost velvety, like the specimen below. If you move your hand across the surface it’s a bit like stroking an animal’s fur. Spores are released from the pores on the lower surface of the fruitbody.

Shaggy Bracket, Inonotus hispidus

Fresh, young Shaggy Brackets, Inonotus hispidus, on an Ash tree. 24th September 2024.

Ageing Fast

But the brackets soon darken and become more coarsely hairy.

I kept track of a Shaggy Bracket on an old Apple tree on our allotment site this summer. I first noticed it on 6th August.

Shaggy Bracket, Inonotus hispidus

Shaggy Bracket, Inonotus hispidus, 6th August 2024.

As it grew it flattened out and developed a softly hairy top.

Shaggy Bracket, Inonotus hispidus

Shaggy Bracket, Inonotus hispidus. 13th August 2024.

After another month (13th September) the bracket was dark on top and had lost its youthful softness (note 3).

Shaggy Bracket, Inonotus hispidus

Shaggy Bracket, Inonotus hispidus. 13th September 2024.

A fortnight later it had darkened still further, but looked lovely after rain (the cause of the drops underneath, rather than guttation).

Shaggy Bracket, Inonotus hispidus

Shaggy Bracket, Inonotus hispidus. 26th September 2024

By late autumn Shaggy Brackets have become dry and blackened. The top surface now resembles a disreputable old rug.

The first Shaggy Brackets I saw looked like this and when I saw my first young specimen a year or two later I was surprised at the difference in appearance and texture.

Old Shaggy Brackets, Inonotus hispidus, on a Whitebeam trunk

Old Shaggy Brackets, Inonotus hispidus, on a Whitebeam trunk. November 2019.

Shaggy Brackets remain on their host tree in the winter but eventually they fall to the ground. I sometimes find them on road verges when out on a walk or bike ride, usually beneath an Ash tree.

Fallen brackets can survive for a considerable time and I still have an old fruitbody from summer 2022. It is on the ground in a corner of my allotment and provides shelter for a family of woodlice and a Leopard Slug.

Old, fallen Shaggy Bracket, Inonotus hispidus.

Old, fallen Shaggy Brackets on the ground beneath an Ash tree.

White Rot

Unfortunately for the host tree, Inonotus hispidus causes a white rot in the trunk, simultaneously breaking down cellulose, hemicellulose and lignin, sometimes preceded by a “soft-rot” phase, a local breakdown of cell walls. The Newcastle Tree services website calls Shaggy Bracket “a slow assassin”.

The severity of the damage will depend on the tree. Branches of Ash trees (Fraxinus) often snap or break and trees have to be felled if there is danger to passers by, but Plane trees (Platanus) are more resilient and branches are less likely to fall, even when hollowed out.

The bracket’s attachment point on the tree trunk often remains darkened after the bracket has fallen. A sunken canker, caused by destruction of cambium, can form beneath the bracket, as shown in a photograph on the TMA Services website.

Inonotus hispidus may not fruit every year so clues like fallen brackets and darkened areas on tree trunks and branches can provide valuable clues to arborists inspecting trees to assess their health and safety (note 4).

Shaggy Bracket fruitbodies usually grow from quite high up the trunk or on the upper branches of the tree and this is the part of the tree that rots. However, last week I found a Shaggy Bracket at the base of an Ash tree, presumably growing from where the tree had been damaged by someone cutting the roadside verge.

Shaggy Bracket, Inonotus hispidus

Shaggy Bracket, Inonotus hispidus, growing at the base of an Ash tree. 14th September 2024.

Confusion Unlikely

The Wild Food website describes Inonotus hispidus as “almost unmistakable when young, but when its is dry, there are a few possible confusions”. The two most likely are:

  • Chaga, the sterile sclerotium (conk) of Shaggy Bracket’s relative Inonotus obliquus. It usually grows on Birch (Betula) trees and is rare in England but more common in Scotland. The inside is reddish brown when cut but it doesn’t have the tubes and pores of the Shaggy Bracket’s fruitbody.
  • An old and dry fruitbody of Dyer’s Mazegill (Phaeolus schweinitzii). This does have tubes and pores but normally has a noticeable stem. Dyer’s Mazegill is primarily a root parasite of conifers and is rarely found on broadleaved trees.

I have never needed to check any microscopic features of Inonotus hispidus but the First Nature website gives details of pores, tubes and spores and the book ‘Poroid Fungi of Europe’ (note 1) has many more details. The First Nature and Nature Spot websites have more photographs of Shaggy Bracket fruitbodies.

“Shaggy Fibrous Ear”

The generic name Inonotus comes from ino– (fibrous) and ot (an ear). The specific name hispidus comes from Latin and means stiffly hairy, shaggy or spiny. Alternative English names include Shaggy Polypore, Velvet Fungus and, in the United States, Inonotus Canker.

In the British Isles, Inonotus hispidus is widespread and common in England but scarcer in Ireland, Wales and Scotland. It is common in south-western and central Europe and southern Scandinavia and can be found in many parts of Asia and North America.

The Shaggy Bracket isn’t an edible fungus – it’s just too tough. But it’s a lovely sight to behold, even if its growth can have unfortunate consequences for the host tree.

Notes

Note 1 – In ‘Poroid Fungi of Europe’ Ryvarden and Melo give oaks (mainly Quercus robur and Quercus petraea) as the main host trees in southern and central Europe. Other deciduous hosts are Apple (Malus, particularly on the Iberian peninsula), Sweet Chestnut (Castanea), Beech (Fagus) and Pear (Pyrus, in Sweden). In North America and former Yugoslavia Abies (fir trees) are the preferred host. L. Ryvarden & I. Melo (2022). ‘Poroid Fungi of Europe’. 3rd edition. Fungiflora, Oslo, Norway.

In the UK, Ash (Fraxinus excelsior) and Plane (Platanus) are major hosts and Walnut (Juglans), Whitebeam and its relatives (Sorbus) and Sycamore (Acer pseudoplatanus) are also used. Guy Watson & Ted Green (2011). ‘Fungi on Trees: An Arborists’ Field Guide’. Arboricultural Association, Stonehouse, Gloucestershire.

Note 2 – Like its relative the Oak Bracket, Pseudoinonotus dryadeus, that I wrote about in October 2021.

Note 3 – This is the stage of development shown in the Sterry and Hughes’ book ‘Collins Complete British Mushrooms and Toadstools’.

Note 4 – On our allotment site fruitbodies appeared in the summer of 2022 but then skipped a year and more were produced this summer.