The family Thelypteridaceae presents considerable species richness throughout the hillside forests and coastal plains of Brazil, as well as in the forests of its southern plateau. This study was based on material collected in 24 trips to various regions within the state of Mato Grosso, as well as material deposited in the principal Brazilian herbaria and in other herbaria. The genus Thelypteris, represented in this study by the subgenera Amauropelta (Kunze) A.R. Sm., Cyclosorus (Link) Morton and Steiropteris (C. Chr.) K. Iwats., comprises 11 species in Mato Grosso and surrounding regions. Keys for identification, descriptions and references to illustrations of diagnostic characters are presented.

Thelypteridaceae Pic.Serm. está representada no Estado do Mato Grosso pelos gêneros Macrothelypteris e Thelypteris, este último com cinco subgêneros Amauropelta (Kunze) A.R. Smith, Cyclosorus (Link) C.V. Morton, Goniopteris (C.Presl) Duek, Meniscium (Schreb) C.F.Reed e Steiropteris Iwats. O presente estudo discute os representantes dos subgêneros Goniopteris (C.Presl) Duek (seis espécies incluindo uma de ocorrência provável) e Meniscium (Schreb.) C.F.Reed (seis espécies). São apresentadas chaves de identificação, descrições, referências a ilustrações com caracteres diagnósticos, bem como comentários sobre a sua distribuição geográfica.

Thelypteridaceae Pic.Serm. is represented in the state of Mato Grosso, by the genera Macrothelypteris and Thelypteris, the latter represented by five subgenera Amauropelta (Kunze) A.R. Smith, Cyclosorus (Link) C.V. Morton, Goniopteris (C.Presl), Meniscium (Schreb) C.F.Reed and Steiropteris Iwats. This study discusses the representatives of the subgenera Goniopteris (C.Presl) Duek (six species, including one probable occurrance in the state) and Meniscium (Schreb.) C.F.Reed (six species). Identification keys, descriptions, references to illustrations with diagnostic characters are presented together with comments on geographic distribution.