Okra, Mandacaru, Planta-pedra and Sisal are plant species found in Brazil that are capable of accumulating water in the stem, leaves or even roots, known as succulents.Now, these four varieties are being honored by the Post Office through a special seal of the Mercosul Series: Fauna and Flora – Succulents.It is estimated that there are more than 12,000 species of succulents distributed mainly in southern and eastern Africa, in the Andes, in Brazil, in Mexico and in the deserts of North America.In Brazil, they are found from the rocks of Rio Grande Sul to the Amazon rainforest.According to Correios, succulence, which has this ability to accumulate water, is a characteristic highly associated with resilience.That's why it is so present in plants that inhabit arid regions of the globe, because the lack of water is the biggest factor that prevents their survival.Because they only grow in very restricted places, most succulents become very susceptible to habitat loss and climate change and, as a consequence, many are threatened with extinction.Preserving these species could also represent the future of agriculture.Like sugarcane, these plants have the ability to accumulate a lot of sugars that can be converted into biofuels, with the difference that they use up to 80% less water than traditional crops.Among the four succulents honored with the seal, two are native to Brazil.Okra-da-lapa (Uebelmannia pectinifera) is one of the rarest cacti of the Brazilian flora, found only in the rocky fields of the Espinhaço Range in Minas Gerais.The subspecies with yellow spines is even rarer and is only native to the municipality of Diamantina-MG.Mandacaru (Cereus jamacaru) is one of the most typical cacti in the Brazilian semiarid landscape, which can exceed 10 meters in height.It is found from Piauí to Minas Gerais, but it can be cultivated in practically all of Brazil.It has already been widely used in civil construction and now stands out for its biotechnological potential in the cosmetics and food industry.Another honoree, the Stone Plant (Lithops lesliei), is native to desert regions in Namibia and South Africa, which has numerous morphological and physiological adaptations to thrive in extreme environments.This succulent presents aspects of stones (mimics) and, thus, avoids being depredated.It is estimated that there are around 300 species of Lithops, distinguished by the different patterns of their leaves.Also present in Brazil, Sisal (Agave sisalana) is native to the Mexican semi-arid region and produces a fiber known among Brazilians as Sisal.Obtained from the leaves of Agave sisalana, its cultivation is of great importance, being often the only alternative with economic gains in the Brazilian semiarid region.Today, Sisal is used mainly in rope making and its bagasse has shown potential for bioinsecticides, mannocellulose and even biogas.This was the 14th post office philatelic release of 2022 (intended for collectors).With a print run of 128,000 copies, the stamps are now available for sale at the Correios virtual store and, soon, at the main agencies in the country at a cost of R$ 2.60 each.