“Oh good”, I thought. “A nice and easy fungus to identify.”

We were walking through the woods at Strumpshaw Fen RSPB Reserve on Tuesday when we spotted a beautiful red cup fungus, growing on pieces of dead, moss covered Rhododendron wood.

I was pretty certain that this was the Scarlet Elfcup, Sarcoscypha austriaca, and I thought I’d confirmed this when I consulted my copy of “Collins Complete Guide To British Mushrooms & Toadstools” by Paul Sterry and Barry Hughes (one of the best general fungi identification guides at the moment).

It was only when I looked on the internet when researching this blog post that I found out that, as so often with fungi, life isn’t quite so simple. As well as the Scarlet Elfcup, Sarcoscypha austriaca, there is the Ruby Elfcup, Sarcoscypha coccinea. Both species can be found on dead logs and twigs in damp, shady places, usually partly buried in moss. They can be found from early winter into early spring: a real treat to discover when various shades of brown are the norm.

In the species accounts on the First Nature website, Pat O’Reilly describes the two species as “macroscopically almost identical”. The colour of both species can vary from pale orange to deep red and although Scarlet Elfcups are sometimes bigger than Ruby Elfcups, there is a great deal of overlap in size, so neither of these characteristics is a reliable way to separate the two species. But help is at hand…

If I had examined the outer surface of the cups, I might have been able to tell which Elfcup I had found. The Ruby Elfcup (S. coccinea) is covered in a matted felt of tiny uncoiled hairs, while the Scarlet Elfcup (S. austriaca) has hairs that are coiled, rather like a corkscrew. Under a microscope, the spores of both species are elongated ellipsoids but some of the spores of the Ruby Elfcup (S. coccinea) have a hammerhead appearance at the ends (the conidial buds). As with many groups of fungi, DNA sequencing has been used in recent years to reveal previously unknown relationships between members of the genus Sarcoscypha [see note 1, below]. 

Elfcups are Ascomycete fungi – part of the family Sarcoscyphaceae in the Order Pezizales, the Cup Fungi. Other well-known Cup Fungi include the Orange Peel Fungus, Aleuria aurantia, which grows on disturbed ground and bears an uncanny resemblance to a piece of discarded orange peel.

Both the Scarlet Elfcup and Ruby Elfcup are generally reckoned to be edible, though they must be cooked first. I haven’t tried them (and, if they are growing in a nature reserve, neither should you).

WildFoodUK describes the taste as “mild, mushroomy”, which is only a faint recommendation, but the colour would add drama to the plate. There are several recipes on the internet, including Roast turbot with garlic shoots and scarlet elf cups, Fillet of sea bass with scarlet elf cup, wild garlic and spring herbs and Elf Cups Stuffed with Egg and Three Cornered Leek. (All three use other seasonal ingredients and use either Wild Garlic or Three-cornered Leek to give a bit of Allium flavour.)

The colour of Elfcups is due to five different carotenoid pigments, including betacarotene (also found in carrots and many plants) and plectaniaxanthin. It is the latter compound that is mainly responsible for the red colour.

Elfcups have sometimes been used to make table decorations. The fungus was also used as a traditional medicine by Native Americans, ground up into a powder and used as a styptic to heal the navels of unborn children.

Or you can just leave them where they are, to brighten up woodland and bring cheer to the darkest months of the year.

Note 1 – See, for example, “Relationships among Sarcoscypha Species: Evidence from Molecular and Morphological Characters” (Francis A. Harrington, Mycologia Vol. 90, No. 2 (Mar. – Apr., 1998), pp. 235-243) and “Phylogenetic Relationships within Sarcoscypha Based upon Nucleotide Sequences of the Internal Transcribed Spacer of Nuclear Ribosomal DNA” (Francis A. Harrington and Daniel Potter, Mycologia Vol. 89, No. 2 (Mar. – Apr., 1997), pp. 258-267).