Cladonia firma (Nyl.) Nyl.
Cladonia foliacea var. firma (Nyl.) Vain.
Cladonia nylanderi Cout.
Primary thallus tufted, squamules 0.4-1 cm tall, indented and recurved tips, markedly rolled-up when dry in small cushions looking like a chrysanthemum flower, upper surface grey-green, grey-blue, lower surface whitish tinged with grey-violaceous all over the surface, notably on old dry specimen. Podetia rather scarce, 1-3 mm tall. Apothecia dark brown, nodulous. Photobiont: Trebouxioid. C-, K+ yellow, KC-, Pd+ red. Quite common in our prospection area due to its coastal and oceanic trends; on calcified dunes, alkaline or weakly acidic soils. Resembles to Cladonia foliacea of which the lobes are larger, the upper surface greener, the lower surface whiter and K-, resembles also to Cladonia cervicornis subsp. cervicornis which is also K+ yellow but with larger and thicker lobes indented only at tips, with a lower surface dull whitish, blackened at their base, frequently fertile and common on acid grounds.*