Studies on Colombian cryptogams XVIII. The genus Stereocaulon (Schreber) Hoffmann (Lichenès)

Nineteen species of Stereocaulon are treated from the northern Andes, mainly from Colombia. Descriptions and keys are given, with notes on the north-Andean distribution and ecology. Seven species are new for the Colombian flora, viz. St. atlanticum, St. claviceps, St. corticatulum (chem. strain with atranorin and perlatolic acid), St. delisei, St. microcarpum, St. pachycephalum and St. pomiferum. St. crambidiocephalum is reported for the first time from Costa Rica, as is St. didymicum from Venezuela, and St. delisei is reported for the first time from the New World (Colombia and Costa Rica). St. cornutum Müll. Arg. is reduced to synonymy under St. pityrizans Nyl.