Species diversity of the genus Riccia L. (Marchantiales, Ricciaceae) in Maranhão state, Brazil

Abstract

Ricciaceae is a little-known liverwort family in northeastern Brazil. Fieldwork in 4 localities in Maranhão state yielded 4 species of Riccia, with 2 taxa, R. mauryana and R. weinionis, representing new state records. This paper describes the species diversity of the genus Riccia in Maranhão state, and provides descriptions, ecological notes, and illustrations for each species.

Diversity of thalloid liverworts in Brazilian Savanna of Parque Nacional da Chapada das Mesas, Maranhão, Brazil

“…In our study area, we found seven species of thalloid liverworts, which are distributed in six genera and six families. These seven species represent 16% of the thalloid liverwort species in northeastern Brazil, a 57% increase in the number of thallose species known from Maranhão state (Silva et al 2018; Flora do Brasil 2020). Most of the species found in our study are Neotropical in distribution, but Cyathodium cavernarum Kunze has a pantropical distribution (Gradstein and Costa 2003;Bischler-Causse et al 2005; Söderström et al 2020).…”

“…However, R. vitalii can be easily distinguished from R. weinionis by the form and ornamentation of the spores. In R. vitalii, the spores are subspherical to subtetrahedral, with a granular proximal face and an evident trilete mark, whereas in R. weinionis the spores are tetrahedral with a proximal face with few areolas and without a trilete mark (Silva et al 2018). Distribution and ecology.…”

“…To date, only one inventory of bryophytes has been undertaken in this park, which focused on mosses (Oliveira et al 2018a). Contrary to its ecological richness, only 26 species of liverworts have been recorded in the state, with just six of them being thalloid liverworts (Silva et al 2018;Flora do Brasil 2020). This low number of species is probably due to the scarcity of taxonomic studies in Maranhão on this group.…”

“…All these species belong to the family Ricciaceae. The only taxonomic study focusing on thalloid liverworts in Maranhão was by Silva et al (2018), but it only included species of the genus Riccia (five species).…”

New records of Aristolochia bahiensis F.Gonzalez for the State of Maranhão, Brazil

“…;Nascimento et al, 2018b. ;Nascimento et al, 2019;Nascimento et al, 2020;Oliveira et al, 2018;Salazar-Ferreira et al, 2020;Silva et al, 2016;Silva et al, 2018a;Silva et al, 2018b. ;Silva-Moraes et al, 2019).…”