Cladonia foliacea (Huds.) Willd. subsp. foliacea

    Primary thallus composed of squamules, up to 0.5-2 cm tall, recurved, indented and incised apices, with dark-brown to black marginal hairs forming tufts, upper surface grey-yellowish, green-yellowish, lower surface pale yellow (whatever the moisture level). Podetia up to 5-10 mm tall, understated and hardly visible, regular, smooth, gradually flared from the base. Apothecia brown, on top of scyphi. Pycnidia frequent, dark-brown. Asci 37-50 x 9-11 µm,with a large I+ apex. Ascospores fili-fusiform, 10-15 x 3-5 µm. Photobiont: Trebouxioid. C-, K-, KC+ yellow, Pd+ red. Coastal trends in our prospection area, on sandy acidic soils near rocks or in their crevices. N.B. Cladonia foliacea subsp. endiviifolia has larger squamules 1.5-3 cm tall,  0.2-1 cm wide and grows on more calcareous or less acidic soils, but many intermediate specimen may exist that hardly can be distinguished (and authors do not always agree about the criteria to be used to identify each subsp., that in fine are only, according to molecular analyses, different morphs of the same species). See also Cladonia convoluta that would also be another more thermophilic morph of the same highly variable species, growing on calcareous grounds and with folded but little indented squamules. In case of calcareous soils and lower surface markedly white without yellow tinge, K+ yellow > red, see Cladonia symphycarpia. Cladonia subcervicornis is K+ yellow and has thicker squamules whereas  Cladonia firma  is also K+ yellow but grey-violet.*