EN
The paper is based on field studies dealing with the lichen genus Cladonia Hill ex P. Browne (Cladoniaceae) carried out by the author in the region of Spitsbergen in 2002 as well as taxonomical work and revision of herbarium material, collected during several earlier Polish polar expeditions to this part of the Arctic. As the result not reported so far from the island species Cladonia stygia (Fr.) Ruoss, C. trassii Ahti, C. verticillata (Hoffm.) Schaer. have been determined. Besides, the presence of very rarely recorded taxa C. crispata var. cetrariiformis (Delise) Vain., C. merochlorophaea Asahina and Cladonia symphycarpia (Flörke) Fr. is confirmed and their new localities are given. Furthermore, the presence of C. coccifera s.str. is also substantiated.