Thursday, March 1, 2012

King Alfred's Cakes

We found these King Alfred's cakes Daldinia concentrica in woodland beside the River Tees at Egglestone this afternoon. This is a strange fungus because it's perennial, adding successive layers of spore-producing tissue onto its surface, so if you cut one in half you see concentric layers - hence the Latin specific name. The spores are shot out from microscopic flask-shaped containers called asci embedded in the surface that act like pop-guns. This fungal artillery operates most vigorously at night and the best way to see how well it works is to put one of these woody fungi in the middle of a large sheet of white paper in a warm room overnight - in the morning the surrounding paper will be covered in a sooty layer of spores. You can see some microscope images of the fungal structures here.

The alternative common name is 'cramp balls', which relates to an old superstition that if you carried one of these in your pocket it would protect you against muscular cramp - just the thing for marathon runners?

Daldinia concentrica typically grows in dead ash trees.


  1. These were by far the most common fungus in our local woodland last autumn (and still remain, of course).

  2. No so much ash in woodland around here as in you locality, maybe John....