RESUMO O tratamento taxonômico das espécies do gênero Casearia ocorrentes no estado do Rio de Janeiro é apresentado. Foram realizadas observações de campo, coleta de material botânico e análise de coleções de herbários nacionais e internacionais. São apresentados chave de identificação, descrições, ilustrações, dados sobre distribuição geográfica, floração e frutificação, nomes vulgares e comentários a respeito de cada táxon. Doze espécies foram reconhecidas: Casearia arborea, C. commersoniana, C. decandra, C. lasiophylla, C. luetzelburgii, C. melliodora, C. obliqua, C. oblongifolia, C. pauciflora, C. selloana, C. sessiliflora e C. sylvestris. C. luetzelburgii e C. selloana são registradas como novas ocorrências no Rio de Janeiro, enquanto C. sessiliflora é endêmica para o estado. Casearia sylvestris var. lingua foi tratada como sinônimo de Casearia sylvestris.

The shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora.

Casearia genus (Salicaceae) is found in sub-tropical and tropical regions of the world and comprises about 160-200 species. It is a medicinal plant used in South America, also known as "guaçatonga", "erva-detiú", "cafezinho-do-mato". In Brazil, there are about 48 species and 12 are registered in the State of Rio de Janeiro, including Casearia sylvestris Sw. There are many studies related to the chemical profile and cytotoxic activities of extracts from these plants, although few studies about the antifungal potential of the essential oil have been reported. In this work, we have studied the antifungal properties of the essential oil of C. sylvestris leaves, as well as of their fractions, against four yeasts (Saccharomyces cerevisae, Candida albicans, C. glabrata and C. krusei) for the first time. The chemical analysis of the essential oil revealed a very diversified (n = 21 compounds) volatile fraction composed mainly of non-oxygenated sesquiterpenes (72.1%). These sesquiterpenes included α-humulene (17.8%) and α-copaene (8.5%) and the oxygenated sesquiterpene spathulenol (11.8%) were also identified. Monoterpenes were not identified. The fractions are mainly composed of oxygenated sesquiterpenes, and the most active fraction is rich in the sesquiterpene 14-hydroxy -9-epi-β-caryophyllene. This fraction was the most effective in inhibiting the growth of three yeast strains.

New Species of Casearia (Salicaceae) from Southeastern Brazil 180 Novon ovate to cucullate; pedicels ca. 3 mm, terete, basally yellow, 1(-1.5) mm, sparsely pilose, free, anthers articulate, white, hirsute. Floral buds oblong-lanceo-yellow, oblong, with a minute gland at the apex, late, sparsely tomentose; flowers bisexual; sepals 5, glabrous; disk lobes yellow, ca. 1 mm, oblong, connate ca. 3.5 X 1.2 mm, fused basally, ovate, greenish at the base of the sepals and alternate with filaments, base and tomentose internally; stamens 10, filaments trichomes sparse, hirsute, white, the style slender, Leaf base 7X05 1 d tth D trb tin and habitat. Casearia ,

Field studies and examination of herbarium specimens have led to a taxonomic revision of the Casearia ulmifolia Vahl ex Vent, complex (Salicaceae). A new species circumscription is presented for C. ulmifolia, C. cotticensis Uittien is reestablished, and one new species, C. murceana R. Marquete & Mansano, is described from Para, Brazil. Morphological descriptions, a taxonomic key, geographical distributions, diagnostic characteristics of the species, and illustrations are provided.