Following the recent first find of Sphagnum obtusum Warnst. in the department of Cantal in France, habitat conditions and distribution in France of this very rare taxon are provided. Sphagnum obtusum is reported with certainty from only three French departments, Jura, Lozère and Cantal. The original community is made of a complex assemblage of : 1 - turficolous and basiphilous taxa, 2 - spring taxa, 3 - taxa clearly linked to groupings that are in the process of stabilization. Known populations should receive statutory protection.