Geoglossum

Geoglossum is a genus of fungi in the family Geoglossaceae. They are commonly called earth tongues. The type species is Geoglossum glabrum. Geoglossum species are distinguished from the related genus Trichoglossum by the lack of setae on the spore bearing surface. Geoglossum species are characterized by dark, club-shaped, terrestrial ascocarps with a fertile hymenium continuing downward from the apex of the ascocarp along the stipe, eventually intergrading with a sterile stipe. The ascospores of Geoglossum range from translucent to dark brown, and are fusiform, and multiseptate. Identification of species is based on the gross morphology of the ascocarp, color and septation of the ascospores, and shape and ornamentation of the paraphyses.

==Taxonomy== Geoglossum was described by Christian Hendrik Persoon in 1794, who created the genus to accommodate Clavaria ophioglossoides L. and three other species: Geoglossum hirsutum (now Trichoglossum hirsutum (Pers.) Boud.), Geoglossum lilacinum (now Thuemenidium atropurpureum (Batsch) Kuntze), and Geoglossum viride (now Microglossum viride (Pers.) Gillet). Persoon expanded the genus in several subsequent publications and the name was sanctioned by Elias Magnus Fries in his 1821 Systema Mycologicum I. Several mycologists have treated the genus extensively since Persoon's first work, including George Edward Massee, Elias Judah Durand, Curtis Gates Lloyd, Fred Jay Seaver, and Edwin Butterworth Mains.