I went looking for Fly agaric, the mushroom everyone recognises but which is surprisingly uncommon where I live; I found none but, almost immediately on arrival at north Cardiff’s Cefn Onn Park, I did spot this large log covered in small black button-like fungi.

These are the fruit of the fungus Black bulgar (Bulgaria inquinans), also known as Rubber buttons and Bachelor’s buttons. According to the First Nature website, they are known as Black Jelly Drops or Poor Man’s Licorice in the United States, though the site also cautions readers not to be fooled by those names – these fungi are not edible and may, indeed, be toxic.

As you can see in the photo above, the fruit bodies look a bit like short tacks; they start out flat on top but come to resemble little cups. The outer surface is, initially, brown and scaly looking but, as they age, they become black, blobby when wet, but tougher and rubbery when dry. Black bulgar is described as common, and can be seen, mostly on fallen Oaks but also on a few other tree species, from autumn through to spring.