I found Epispathidium papilliferum in moss taken from a tree trunk. The moss was moistened with water from the Simmelried. It took 2 weeks for a population of Epispathidium papilliferum to develop. Besides Epispathidium papilliferum, I was only able to detect large numbers of Halteria grandinella, Colurella uncinata, and Cyclidium glaucoma in the moss sample.

Originally, Epispathidium papilliferum was described as Spathidium papilliferum by Kahl in 1930. In 1984, the species was then transferred to the genus Epispathidium by Foissner.

The specimens of my population were 150–200 µm long. A characteristic feature of Epispathidium papilliferum is the 3 papillae of the oral bulge. However, in my population, the dorsal papilla was only weakly developed (s. fig. 3 a). This observation was also made by Kahl and Foissner, who also found specimens with only two papillae. There is evidence that the number and shape of the papillae depend on the food supply. Kahl reported that starving forms of Epispathidium papilliferum even have finger-shaped, elongated papillae.

The nodules of the macronucleus were very numerous and small in my specimens. They were also not easy to recognize in heavily compressed specimens (s. fig. 4). However, the small, spherical micronuclei were always clearly visible (s. fig. 4). The straight, rod-shaped extrusomes in my population were 11–13 µm long and thus corresponded exactly to the descriptions by Jang et al. (2017), Kahl and Foissner (s. fig. 5).