Diversity of thalloid liverworts in Brazilian Savanna of Parque Nacional da Chapada das Mesas, Maranhão, Brazil Author Fernandes, Rozijane Santos Author Silva, José Augusto dos Santos Author Ottoni, Felipe Polivanov Author Pinheiro Costa, Denise text Check List 2021 2021-01-07 17 1 45 58 http://dx.doi.org/10.15560/17.1.45 journal article 10.15560/17.1.45 1809-127X Symphyogyna leptothelia Taylor Figure 6A–F Material examined: BRAZIL – Maranhão • Carolina, Parque Nacional Chapada das Mesas , passagem da Dona Lena 07°03′45″S , 047°15′16″W ; alt. 230 m ; 07 Jun. 2018 ; J . A . S Silva 292 col.; CCAA 1528 . • ibid.; 04 Feb. 2020 ; J . A . S Silva 491 col.; CCAA 2628 . Identification. Plants rupicolous. Thallus dichotomous, dark green, 21–26 × 2.2–5 cm , with central midrib; main axis convex to flat, 0.1 mm wide, with single prosenchyma band; wings large ( 0.2 mm ); dorsal surface in cross-section without epidermal pores and air chambers; ventral surface with chlorophyllose cells; margin toothed; teeth with 5 or 6 cells; dorsal scales covering the archegonium. Sporophyte not seen. Symphyogyna leptothelia grows prostrate on soil, and the thallus has wide undulate wings, a prominent central midrib with a single strand of prosenchyma tissue, and a toothed margin. Symphyogyna aspera Steph. is sometimes confused with S. leptothelia due to the prostate habit, dark green thallus, and toothed margin. However, S. leptothelia has entire wings that are not divided into segments and a toothed thallus apex, while S. aspera has lobate wings, divided into segments, and a non-toothed thallus apex. Distribution and ecology. Neotropical ( Uribe and Aguirre 1995 ; Gradstein and Costa 2003 ; GBIF.org 2020; Tropicos.org 2020). Brazilian biomes and states: Atlantic Forest ( Espírito Santo , São Paulo , and Paraná ), Brazilian Cerrado ( Goiás , Maranhão ; new data), Mato Grosso do Sul , Minas Gerais ) ( Flora do Brasil 2020 ). We collected this species on shaded rocks near the sandbank of a stream in a riparian gallery forest. Ricciaceae