[3] While it is found in various regions of the UK, it is considered potentially threatened in parts of the lowlands due to habitat loss.

[4] Verrucaster lichenicola, described by Friedrich Tobler in 1913,[5] was proposed to be a fungus with waxy pycnidia and hyaline conidia lacking septa.

The rediscovery of the type material more than a century later revealed that what Tobler thought to be a lichenicolous fungus was instead pycnidia of Cladonia macilenta, and thus the two taxa are placed in synonymy.

It is often mistaken for Cladonia polydactyla,[4] because some morphs of that species can lack cups, particularly when pollution-stressed, shaded, or juvenile.

But C. macilenta can be differentiated by coloration (C. macilenta is typically white or grey, while C. polydactyla is typically blue-grey) or by the reproductive structures (soredia) which are granular in C. polydactyla and more mealy (farinose) in C.