Helianthemo cani-Festucion pallentis
(syntax.syn.)
– fes16 M. Chytrý does not support the concept of this alliance and prefers to include it within the Alysso-Festucion pallentis. The basic-acidic gradient in Bohemia, from where this alliance was described, is continuous, as there are basalts and similar volcanic rocks with chemistry and physical properties not very different from Silurian-Devonian limestones and calcareous shales. J. Klika in his classical works (1933 and others) included relevés from Central Bohemian limestones and volcanic rocks to the same associations, because he observed high similarity in floristic composition. The original diagnosis of the Alysso-Festucion pallentis also includes vegetation from basic igneous rocks, not only from strongly acidic rocks, which indicates that a single alliance for the xerophilous rocky grasslands in Bohemia and the adjacent areas of the Hercynicum is sufficient. (M. Chytrý).