Description: Primary thallus squamulose, persistent, the squamules middle-sized, 2-7 mm long (rarely more) and up to 4 mm wide (usually less), thin (less than 0.4 mm thick), irregularly lobed or incised, the tips rounded, mostly ascending, never forming a subrosulate crust, greenish grey above, white beneath. Podetia goblet-shaped, hollow inside, greenish grey, esquamulose, 0.5-3(-5) cm tall, with broad cups gradually tapering into short stalks, the cups regular or proliferating from margin, with contiguous to scattered, corticate granules or peltate squamules (schizidia), especially inside the cups. Apothecia frequent, brown, convex. Asci 8-spored, clavate, thickened at apex, with a K/I+ blue tholus and a K/I+ strongly blue outer gelatinous sheath, Cladonia-type. Ascospores 1-celled, hyaline, ellipsoid. Pycnidia dark, semi-immersed on the margins of cups, with a colourless jelly. Conidia cylindrical. Photobiont chlorococcoid. Spot tests and chemistry: four chemotypes are known from Europe (all of them C-, KC-, UV-): K-, P+ red (fumarprotocetraric acid complex, often with additional physodalic acid). 2) K+ yellow, P+ red (atranorin and fumarprotocetraric acid complex). 3) K-, P+ red (fumarprotocetraric acid complex and psoromic acid), 4) K+ yellow, P+ red (atranorin, fumarprotocetraric and psoromic acids). Chemotype 1) is the most frequent.
Note: a widespread, very polymorphic, holarctic species with a wide altitudinal-latitudinal range, which is common throughout in Italy. In its present circumscription, however, the species appears to be heterogeneous. According to Stenroos & al. (2019) molecular data do not support the distinction of C. monomorpha (see also Burgaz & al. 2020). The record of Cladonia borbonica Nyl. from Calabria by Puntillo (1995, 1996) refers to a form of the C. pyxidata complex (Ahti in litt.).