The taxonomic utility of two characters not previously used for identification of Geastrum species is evaluated. First, macrochemical spot tests with chemicals detecting phenoloxidase enzymatic activity (1-naphthol, guaiac gum, and syringaldazine), are performed. In addition, the usefulness of the crystalline deposits from the rhizomorphs, formed by calcium oxalate as monohydrate or whewellite, and dihydrate or weddellite, was evaluated. These features provide valuable data to distinguish some taxa difficult to separate using traditional morphology, such as G. lageniforme, G. saccatum, and G. triplex.