First described in 1894, it is distinguished by its cushion-like growth habit and a prominent primary thallus made up of large, erect, greyish-green squamules with darkened undersides.

The species typically grows on thin layers of humus in rock crevices along coastal areas, particularly in heath environments, where it can become locally abundant.

In his description, he provided a diagnosis distinguishing it by its primary thallus having medium to large squamules that turn yellow when treated with potassium hydroxide solution (K).

He noted that the podetia (upright stalks) bear scyphi (cup-like structures) and are either simple or proliferate with a few tiers, also showing a yellow reaction with K. Vainio cited earlier reports of the lichen from several European locations, including sites in Sweden, Norway, Britain, and Germany, though he indicated that its complete distribution was still imperfectly known at the time.

The surface is corticate (having an outer layer) and varies from smooth to areolate or slightly warty, with a bright appearance and occasional squamules on the scyphal margins.

Pycnidia (asexual reproductive structures) are also frequent along the scyphal margins, appearing either sessile or prominent, and produce a hyaline (translucent) slime.

[6] Several other Cladonia species that possess large, squamulose primary thalli may be confused with C. subcervicornis, particularly C. cervicornis, C. macrophylla, C. macrophyllodes, and C. microphylla.

[7] Phylogenetic studies have shown that C. subcervicornis is most closely related to C. firma, with both species containing atranorin and sharing similar distribution patterns.

The species shows a particular affinity for exposed rock surfaces in these coastal areas, where it can become locally abundant and may even dominate the vegetation of suitable habitats.

[7] While primarily distributed throughout Western Europe and the Macaronesian Islands, it occurs very rarely in Eastern European countries, extending from temperate to boreal zones.

[6] A notable inland population exists in Bohemian Switzerland (Czechia), which represents an isolated occurrence far from the species' main Atlantic distribution range.

Genetic studies in western Norway reveal marked differentiation between populations only kilometres apart, indicating that long-distance colonisation is uncommon—even in windswept coastal habitats where spore dispersal might be expected to thrive.