Cladonia arbuscula (Wallr.) Flot. subsp. arbuscula

    Primary thallus granular, hardly visible, evanescent. Secondary thallus shrubby, to 10 cm high, densely branched, with smooth twigs, 2-4 mm diam., branching di, tri or tetrachotomous markedly orientated in one direction, terminal branches short, thin, blunt, pale yellow-greenish when moist, pale greyish almost whitish if dry, with small darker spots. Apothecia very rare, hardly visible, at the tip of twigs, brown. Photobiont : trebouxioide. C-, K-, KC+ yellow, Pd+ golden-yellow. On nutrient-poor acid or decalcified dunes, almost always near pines in our prospection area, also on acid soils in wood pines. N.B. This subsp. is supposed to be mountainous but this is not observed in our prospection area, on the contrary of other mountainous species; in order to compare, we have included two pictures of this species taken in the Alps.

There are also:

     _ Cladonia arbuscula subsp. squarrosa (Wallr.) Ruoss. (= Cladonia sylvatica ss. auct.) which is  C-, K-, KC+ yellow, Pd+ red-rusty. On acid dunes. See this subsp. under its file.

  _ Cladonia arbuscula subsp. mitis (Sandst.) Ruoss. (= Cladonia mitis Sandst.) which is Pd- (seldom Pd+ redish) with grey twigs, thinner, and terminal twigs are not oriented only in one direction. Same habitat. Intermediate specimen with subsp. arbuscula exist and mainly with subsp. squarrosa.

  To compare with Cladonia portentosa which is Pd- and with terminal branchlets less recurved and divergent in all directions and with Cladonia ciliata var. tenuis of which the the terminal branchlets are dichotomous and Pd+ red.  Not to confuse also with Cladonia mediterranea.*