ResumoEste estudo consiste no levantamento florístico de Combretaceae ocorrentes no estado do Ceará, como parte do projeto "Flora do Ceará". O estudo foi baseado na análise comparativa dos caracteres morfológicos de espécimes depositados em herbários, bibliografia, fotos de materiais-tipo, além de coletas e observações de campo. Foram registradas 17 espécies distribuídas em cinco gêneros: Buchenavia (2); Combretum (9); Conocarpus (1); Laguncularia (1) e Terminalia (4). As espécies ocorrem preferencialmente em ambientes mais secos como caatinga, carrasco e floresta estacional. Palavras-chave: distribuição, florística, Combretum, nordeste do Brasil, Terminalia. AbstractWe present the floristic survey of Combretaceae occurring in the Ceará state, as part of "Flora do Ceará" project. This study was based on the comparative analysis of morphological characters of herbarium specimens, bibliography, photo-type material, along with collections and field observations. Seventeen species in five genera were recorded: Buchenavia (2); Combretum (9); Conocarpus (1); Laguncularia (1) e Terminalia (4). The species occurs preferentially in drier habitats like the caatinga, carrasco and deciduous forest.

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.

Although the conservation of tropical biodiversity depends on protected areas, there is still a very large 'gap' of knowledge on the flora of Brazilian reserves, especially in the Northeast region of Brazil. Field and herbarium surveys of the phanerogamic flora of the Ubajara National Park, located on the Brazilian Northeast, were made and analyses on phenology and dispersal syndromes were performed. 418 taxa (213 trees and shrubs, 100 terrestrial herbs, 68 climbing plants, 33 sub-shrubs, two epiphytes, one hemiparasite and one aquatic herb) were recorded. The most representative families were: Fabaceae, Malvaceae, Asteraceae, Rubiaceae and Euphorbiaceae. The annual flowering / fruiting peak hypothesis was not fully confirmed, therefore, the forest may be an important food resource for the fauna all year long (especially in the moister region). Zoochory was the predominant dispersal syndrome in the moister area, whereas, autochory and anemochory together, predominated in the drier area.

Studies related to the allelopathic properties of plants have aroused great interest, since species that have compounds with allelopathic activity can be used as bioherbicides in the control of weeds. In this way, the aim of this study was to evaluate the allelopathic action of Dahlstedtia araripensis on the germination and growth of Calotropis procera and Zea mays. The bioassays were prepared using two 50 g portions of leaves, stem bark and D. araripensis roots, and each part of the plant received a hot treatment (1 L of distilled water at 100 °C) and one part cold (1 L of distilled water at 25 °C). The experimental design consisted of six treatments and the control group. The variables analyzed were: Index of Emergency Speed (IES), germinability, length and occurrence of necrotic radicles. The results indicated that the extracts interfered negatively on the germinability of the seeds, mainly on those of C. procera, since all extracts significantly inhibited its germination. In the seeds of C. procera and Z. mays there was delay in IES. The results indicated that the cold and hot extracts of the distinct parts of D. araripensis affected the development of the seedlings, besides promoting root necrosis. The observed effects may be due to the presence of secondary metabolites detected in the different extracts of D. araripensis. However, further research is required to prove the performance of such compounds, as well as their isolation, for future use asnatural herbicides.

Resumo Apresentamos o levantamento florístico-taxônomico das espécies de Symplocaceae para o estado do Ceará, como parte do projeto “Flora do Ceará: conhecer para conservar”. O estudo foi baseado na análise comparativa dos caracteres morfológicos de espécimes depositados nos Herbários ALCB, EAC, HUVA, IPA, R e UPCB, bibliografias especializadas e imagens de coleções-tipo. Para o estado foram registradas três espécies de Symplocos: S. guianensis, S. nitens e, possivelmente, S. oblongifolia. No entanto, por falta de material reprodutivo não foi confirmada a identificação do último táxon. As espécies ocorrem em vegetação de Floresta Ombrófila Densa e Savana. Symplocos nitens é uma nova ocorrência para o Ceará e foi registrada em duas Unidades de Conservação no estado.