Short Communication Sphaerocarpos muccilloi (Sphaerocarpaceae, Marchantiophyta), a critically endangered species recollected in Rio Grande do Sul, Brazil, and Sphaerocarpos texanus, a new record to Brazil

Sphaerocarpos muccilloi (Sphaerocarpaceae, Marchantiophyta) was described in 1981, being an endemic species and the only species of the family to Brazil. This species is considered as Critically Endangered (CR) according to “Red List of threatened species of the Rio Grande do Sul state”. Sphaerocarpos muccilloi was recorded in three places only in Rio Grande do Sul: Porto Alegre, São Leopoldo and Ivoti (collected from 1963 to 1977). These sites are highly anthropized and the last records being from more than 40 years. After a revision of herbarium specimens and several field trips we recollected S. muccilloi in the Pampa Biome, in Santana do Livramento municipality, at the Ibirapuitã Environmental Protection Area (APA do Ibaratuitã), Mata and Santa Vitória do Palmar municipalities. Another species (S. texanus), not reported to Brazil, was reported now to Paraná state. These new records provide important information about occurrence and distribution of the family to Brazil. Regarding to S. muccilloi, these new records show that the range of occurrence is wider than previous reported. This new data will help the next revision of the Red List of Threatened Species of Rio Grande do Sul and Brazil and will subsidize conservation strategies.


Resumo
Sphaerocarpos muccilloi (Sphaerocarpaceae, Marchantiophyta) foi descrito em 1981 como uma espécie endêmica e única da família no Brasil. É considerada Criticamente Ameaçada (CR) no estado do Rio Grande do Sul, Brasil, de acordo com a "Lista Vermelha das espécies da flora ameaçadas do estado do Rio Grande do Sul". S. muccilloi é citado apenas para 3 localidades: Porto Alegre, São Leopoldo e Ivoti (coletado entre 1963 e 1977), todas áreas hoje altamente antropizadas, sendo a última coleta ocorrida há mais de 40 anos. Após uma revisão em herbários e coletas em campo S. muccilloi foi recoletado no ano de 2017 no Bioma Pampa ( Sphaerocarpos muccilloi E. Vianna (Sphaerocarpaceae, Marchantiophyta) is a Brazilian endemic species that was described in 1981 as a thallose, dioecious species, with female gametophytes with suborbicular thallus with large balloon-like involucres structures around the oosphere, 5-8 mm in length and the male gametophyte is oval, lobed thallus, often colored of purple, with smaller pear-shaped structures around the antheridia, 1-3 mm long gametophytes. The sporophyte develops inside the balloon-like structures on the thallus, the seta is short and the foot is bulbous and embedded in the thallus. It grows in moist and compacted soils, in open and illuminated areas (Vianna 1981 et al. (1986), the vegetation in this area is typical of the Savanna, Steppe and Deciduous Seasonal Forest formations.
The municipality of Mata is also located in the Pampa Biome and has an area of 311.90 km 2 , most of which is occupied by crops (corn, soybeans and rice) and together with the municipality of São Pedro do Sul, it is part of the Paleobotanical Sites of Arenito Mata, created by the Brazilian Commission of Geological and Paleontological Sites in 1978 (Sommer & Sherer 2002). From Triassic age, these "petrified forest" exhibitions attract tourists to the city because they are among the most important records of its kind on the planet, having formed more than 200 million years ago (Sommer & Sherer 2002).
Sphaerocarpos muccilloi was collected in Santana do Livramento municipality, at APA do Ibirapuitã, in Estância da Glória (30º44'59.9"S, 55º34'07.1"W), 227 m altitude, on compacted soil and ravine (Fig. 1). It was collected in the center of the municipality of Mata, in compacted soil of the stairs formed by fossilized wood, associated to Phaeoceros sp. The samples are deposited at three different Herbaria: Herbário Dr. Ronaldo Wasum da Universidade Estadual do Rio Grande do Sul -Litoral Norte (HERW), Herbário do estado "Maria Eneyda P. Kauffman Fidalgo" (SP) e no Herbário da Universidade de Brasília (UB).
The recollection of S. muccilloi after 40 years increased the knowledge about this species and brought a new perspective to its conservation, since there were doubts if the species populations still exist.
We examine herbarium specimens and found another site to S. mucilloi, in Santa Vitória do Palmar, and the occurrence of S. texanus (Fig. 2), not previously reported to Brazil. Sphaerocarpos texanus is widely distributed in Americas and is differentiated by its regular and high partition walls of the spore, in contrast with S. mucciloi that show a small portion of the outer surface of the spore with high partitions. For further details of the characterization of S. texanus see Haynes (1910).
These new data will help in the next revision of the Bryophytes Species List in Rio Grande do Sul and in Brazil as goals of Brazil in the Convention on Biological Diversity (Brasil 2002). Probably these new data will change the status of the S. mucilloi low risk because the range of occurrence was larged increased.