Winter Mushrooming in the Alder Swamp II: Daldinia childiae

These small, stalked Daldinia grow on alder.

My favourite find in our ice-and-snow-covered wetland this winter is a very peculiar little Daldinia. Unlike any I've ever found before, these have stems, or stalks, and a shiny, varnished appearance.

The mystery Daldinia are often warty and varnished.

Daldinia, which belong to the Xylariaceae family, are hard black lumps that grow on wood. Because they're black and roundish and brittle and look like they've been charred, one of their common names is King Alfred's Cakes, which stems from a purported incident in the 12th century when the English monarch, King Alfred, allowed some cakes to burn that a peasant woman—who had kindly offered him shelter from attacking Vikings—had asked him to watch. 

King Alfred's Cakes growing out of the bark of a dead tree.

They're also called Cramp Balls, which I think sounds vaguely rude. Folklore suggests that if you carry some in your pocket you'll find relief from leg or menstrual cramps—or make your pocket black, since these guys shed copious amounts of very dark spores. 

Daldinia species release copious amounts of ascospores at night.

The species I normally find around here in southern Ontario is Daldinia childiae, which is erroneously listed in most field guides as Daldinia concentrica, a European species. Like all Daldinia it's a wood  decayer, or saprobe. They can create intricate dark line drawings inside the wood they've colonized, called "spalting," which is prized by woodworkers. 

Daldinia have concentric rings in their interior.

Daldinia childiae and Daldinia concentrica have a lovely characteristic: when you cleanly cut one vertically, a shimmering display of concentric rings is revealed, like a monochrome jawbreaker. The layer closest to the surface has flask-shaped perithecia, where the spores are produced in asci. The spores are discharged at night, and can do so continuously for a month or two, even during drought conditions. 

So those are your basic Daldinia. But what I found, and what I keep finding, are not at all like the normal ones, which can be up to 8 cm in diameter, are usually dull black when mature, and have a tendency to closely hug whatever dead tree or branch they're growing on. Nope, mine are much smaller (no more than  2 cm in diameter), have a varnished appearance, very noticeable stems, and seem to only grow on standing dead alder.  

The literature, however is confusing. Elements of Daldinia caldariorum are similar, but that species is apparently only found on burnt Ulex wood in Great Britain. Descriptions of Daldinia vernicosa fit in some ways (varnished appearance, stemmed), but, unlike mine, are supposedly easy to crumble between the fingers, and, furthermore, Mycoquebec suggests that, unlike the single layer of perithicia that Daldinia childiae has (or Daldinia concentrica), Daldinia vernicosa has a double layer. 

Wanting to know what species I had, I sent a couple of samples to Jack Rogers of Washington State University. Despite their unusual appearance, they are, in fact, Daldinia childiae. 

References:

Daldinia key and species descriptions at Xylariacea


Walkey, D. G. A., and R. Harvey. 1968. Spore discharge rhythms in pyrenomycetes. IV. The influence of climatic factors. Trans. Brit. Mycol. Soc. 51: 779-786.

Rhoads, A. S. Daldinia Vernicosa—A Pyroxylophilous Fungus, Mycologia, Vol. X November, 191 8 No. 6 D Arthur S. Rhoads

Marion Child, The Genus Daldinia, Annals of the Missouri Botanical Garden
Vol. 19, No. 4 (Nov., 1932), pp. 429-480+482-496