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RESUMO: Renealmia L.f. é um gênero de Zingiberaceae com inúmeros usos, entre eles: ornamental, medicinal e alimentício. Visando ressaltar a importância deste gênero como potencial fonte de recursos agroeconômicos apresenta-se esta revisão sobre aspectos botânicos, ecológicos, farmacológicos, e agronômicos. De um universo de 87 espécies formalmente inseridas em Renealmia, registrou-se indicação de uso popular para 18 destas. Em sua maior parte as indicações de uso estiveram associadas a R. alpinia, R. exaltata e R. guianensis englobando, principalmente, os usos ornamental, alimentício e medicinal. Dentre as 14 espécies com indicação de uso popular medicinal, registram-se pesquisas farmacológicas para apenas quatro: R. alpinia, R. exaltata, R. nicolaioides e R. thyrsoidea. Entretanto, estas pesquisas evidenciam um amplo espectro de bioatividade, com ênfase na ação anticancerígena e antiofídica, especialmente de R. alpinia. Apenas seis espécies foram avaliadas quanto a composição química (R. floribunda, R. guianensis, R. alpinia, R. chrysotricha, R. exaltata e R. nicolaioides), identificando-se perfil químico que corrobora a potencialidade anticancerígena e antiofídica para os representantes deste gênero. Evidenciou-se grande lacuna no que se refere ao conhecimento científico ou técnico para o cultivo de espécies de Renealmia. Isto pode se configurar num impedimento importante na utilização destas espécies como recurso econômico.

ABSTRACT: The Renealmia L.f. is a genus that belongs to the Zingiberaceae with several applications, including the ornamental, medicinal and food ones. Aiming to emphasize the importance of this genus as a potential agro-economic resource, a review of its botanical, pharmacological and agronomic aspects is presented. From 87 species formally inserted in the Renealmia, 20 were registered with popular uses. In general, these popular uses were associated with R. alpinia, R. exaltata and R. guianensis, mainly including the ornamental, nourishing and medicinal uses. Among 14 species with indication of popular medicinal use, pharmacological studies were registered for only four: R. alpinia, R. exaltata, R. nicolaioides and R. Thyrsoidea. However, these studies show a large bioactivity range, with emphasis in the anti-carcinogenic and antiophidic action, especially for R. alpinia. Only six species were analyzed in terms of chemical composition (R. floribunda, R. guianensis, R. alpinia, R. chrysotricha, R. exaltata and R. nicolaioides). Their chemical profiles corroborate the anti-carcinogenic potential for the representatives of this genus. There is a great scientific or technical gap on the cultivation of Renealmia species. This can be an important limiting factor in the use of these species as economical resource.

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This study assessed the accumulation of Cd (II), Hg (II), Cr (VI) and Pb (II) in Gynerium sagittatum (Gs), Colocasia esculenta (Ce) and Heliconia psittacorum (He) planted in constructed wetlands treating synthetic landfill leachate. Sixteen bioreactors were operated in two experimental blocks. Metal concentrations in the influent and effluent; root, stem, branch and leaves of plants were analysed, as well as COD, N-NH4+, TKN, T, pH, ORP, DO, and EC. Average removal efficiencies of COD, TKN and NH4+-N were 66, 67 and 72%, respectively and heavy metal removal ranged from 92 to 98% in all units. Cr (VI) was not detected in any effluent sample. The bioconcentration factors (BCF) were 10(0) -10(2). The BCF of Cr (VI) was the lowest: 0.59 and 2.5 (L kg(-1)) for Gs and He respectively; whilst Cd (II) had the highest (130-135 L kg(-1)) for Gs. Roots showed a higher metal content than shoots. Translocation factors (TF) were lower, He was the plant exhibiting TFs>1 for Pb (II), Cr (T) and Hg (II) and 0.4-0.9 for Cd (II) and Cr (VI). The evaluated plants demonstrate their suitability for phytoremediation of landfill leachate and all of them can be categorized as metals accumulators.

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An ecosystem containing a mixture of species that differ in phenology, morphology, and physiology might be expected to resist leaching of soil nutrients to a greater extent than one composed of a single species. We tested the effects of species identity and plant-life-form richness on nutrient leaching at a lowland tropical site where deep infiltration averages >2 m year(-1). Three indigenous tree species with contrasting leafing phenologies (evergreen, dry-season deciduous, and wet-season deciduous) were grown in monoculture and together with two other life-forms with which they commonly occur in tropical forests: a palm and a giant, perennial herb. To calculate nutrient leaching over an 11-year period, concentrations of nutrients in soil water were multiplied by drainage rates estimated from a water balance. The effect of plant-life-form richness on retention differed according to tree species identity and nutrient. Nitrate retention was greater in polycultures of the dry-season deciduous tree species (mean of 7.4 kg ha(-1) year(-1) of NO(3)-N lost compared to 12.7 in monoculture), and calcium and magnesium retention were greater in polycultures of the evergreen and wet-season deciduous tree species. Complementary use of light led to intensification of soil exploitation by roots, the main agent responsible for enhanced nutrient retention in some polycultures. Other mechanisms included differences in nutrient demand among species, and avoidance of catastrophic failure due to episodic weather events or pest outbreaks. Even unrealistically simple multi-life-form mimics of tropical forest can safeguard a site's nutrient capital if careful attention is paid to species' characteristics and temporal changes in interspecific interactions.

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