File:A slime mould - a Stemonitis species - geograph.org.uk - 1046280.jpg

English: A slime mould - a Stemonitis species This slime mould, belonging to the genus Stemonitis, was growing on a tree stump in dense deciduous woodland. Unfortunately, it is long past its best; however, it still shows some interesting features.

The individual fruiting bodies can be seen to consist of a thin black hair-like stalk topped by a thicker cylindrical part (which bears the spores). The tops of several fruiting bodies have become stuck together. Also, a few of the black hair-like stalks appear on their own, where the top part has fallen off.

The book "Introductory Mycology", by Alexopoulos and Mims, says of the larger Stemonitis species that "many of these species tend to produce their slender sporangia in dense clusters on dead stumps and logs. Their thin, hair-like stalks tend to persist for some time after most parts of the sporangia have weathered away. Stemonitis attained dubious fame at the 1933 World's Fair held in Chicago when placed on exhibit at the Believe It or Not pavilion over the caption 'Hair Growing on Wood – Believe it or not.'"