Genus Mimosa Research Articles

Flavonoids from Mimosa tenuiflora Green Propolis: Chemotaxonomy, Antioxidant, Anti‐Inflammation, Anti‐Bacteria, Mosquito Larvicidal Activity, and In Silico Approach

AbstractPhytochemical study of green propolis alcohol extract of Brazilian Caatinga Mimosa tenuiflora (Willd.) Poir resulted in the separation of six flavonoids, including quercetin 3‐methyl ether (1) and 3,3′‐O‐dimethylquercetin (2), and four flavanones eriodictyol 5‐O‐methyl ether (3), 5,4′‐dihydroxy‐6,7‐dimethoxyflavanone (4), licoflavanone (5), and macarangaflavanone B (6). All these metabolites were first isolated from green propolis and the genus Mimosa. Metabolites 3–4 also established chemotaxonomic significance since they had never been observed in the bean family Fabaceae. Flavones 1–2 showed strong antioxidative activity against DPPH (1,1‐diphenyl‐2‐picryl hydrazyl) radicals with IC50 values of 12.40 and 16.23 μg/mL, respectively. All six isolates showed anti‐inflammatory effects against NO (nitric oxide) production in LPS (lipopolysaccharide)‐stimulated Raw 264.7 cells, in which the activity of flavone 1 was better than the standard dexamethasone (IC50 13.35 μg/mL). Flavonoids 1–3 also strongly controlled the growth of the Gram‐positive bacteria Bacillus subtilis ATCC 6051, and Staphylococcus aureus ATCC 29213 with MIC values of 32–64 μg/mL. Six isolated flavonoids exhibited strong or moderate mosquito larvicidal activity against Aedes aegypti and Ae. albopictus fourth instar larvae with the 24 h LC50 values of 29.62–55.89 μg/mL. By in silico approach, compound 1 was a non‐toxic agent with an LD50 value of 5000 mg/kg.

Chemical profile and evaluation of the pharmacological activity of the dry extract and fraction of ethyl acetate obtained from the leaves of Mimosa caesalpiniifolia

Ethnopharmacological relevanceMimosa caesalpiniifolia (Sansão-do-Campo) is a native species of the caatinga in northeastern Brazil that has been studied for its potential anti-inflammatory and antidepressant activity. It is popularly consumed as a medicinal plant and its pharmacological benefits are evidenced in the literature. Aim of the studyThe present work was carried out to promote the chemical profile and evaluate the pharmacological activity of the dry extract and the ethyl acetate fraction obtained from the dry leaves of Mimosa caesalpiniifolia. Materials and methodsThe leaves were collected in the municipality of Alfenas-MG and subjected to drying, followed by division in a knife mill. The preparation of the dry extract was carried out by the extraction method using simple percolation and the fraction was obtained by liquid-liquid partition. Part of the extractive solution was concentrated in a rotary evaporator followed by a drying process using the spray technique with the addition of colloidal silicon dioxide. The dry extract (33.33%) showed a higher yield in mass when compared to the yield of the ethyl acetate fraction (19.67%). The in vivo pharmacological evaluation was conducted with a total of 82 male Wistar rats that underwent cecal ligation and perforation surgery to induce the inflammatory process. One week after surgery, these animals were treated for 7 days with the dry extract and the ethyl acetate fraction and submitted to behavioral tests (open field and forced swimming). ResultsThe chemical results were obtained through analysis by HPLC-PDA coupled to a mass spectrometer, enabling the verification of the presence of phenolic acids, flavonoids, aglycones, and glycosides, in addition to tannins. This corroborates with data present in the literature for the genus Mimosa sp. Some compounds had their structure determined, where they were identified as catechin (m/z 288.97), cassiaocidentalin A (m/z 560.75), and procyanidin B2 [(epi)catechin–(epi)catechin; m/z 576.83)]. It was found that the animals that were submitted to the treatment did not present statistically significant results, demonstrating that the pharmacological action evaluated in the test was not highlighted in this type of experiment. The groups that underwent treatment had an aggravated locomotor activity. ConclusionsThe results found with the chemical study contributed to the knowledge of the plant species studied. On the other hand, further studies are needed to provide a better understanding of the pharmacological evaluation of Mimosa caesalpiniifolia.

Comparative floral development in Mimosa (Fabaceae: Caesalpinioideae) brings new insights into merism lability in the mimosoid clade.

The genus Mimosa L. (Leguminosae; Caesalpinioideae; mimosoid clade), comprising more than 500 species, is an intriguing genus because, like other members of the mimosoid clade, it presents an enormous variation in floral characteristics and high merism lability. Thus, this study aimed to elucidate the floral development and identify which ontogenetic pathways give rise to merism variation and andromonoecy in Mimosa caesalpiniifolia, M. pudica, M. bimucronata, and M. candollei. Floral buds at various stages of development and flowers were collected, fixed, and processed for surface analysis (SEM). The development of the buds is synchronous in the inflorescences. Sepals appear simultaneously as individualized primordia in M. caesalpiniifolia and in reversed unidirectional order in M. bimucronata, with union and formation of an early ring-like calyx. Petal primordia appear in unidirectional order, with a noticeably elliptical shape in M. caesalpiniifolia. The wide merism variation in Mimosa results from the absence of organs from inception in the perianth and androecium whorls: in dimerous, trimerous, or tetramerous flowers, the additional organs primordia to compose the expected pentamerous flowers are not initiated. The haplostemonous androecium of M. pudica results from the absence of antepetalous stamens from inception. In the case of intraspecific variations (instabilities), there is no initiation and subsequent abortion of organs in the events of reduction in merosity. In addition, extra primordia are initiated in supernumerary cases. On the other hand, staminate flowers originate from the abortion of the carpel. Mimosa proved to be an excellent model for studying merism variation. The lability is associated with actinomorphic and rather congested flowers in the inflorescences. Our data, in association with others of previous studies, suggest that the high lability in merism appeared in clades that diverged later in the mimosoid clade. Thus, phylogenetic reconstruction studies are needed for more robust evolutionary inferences. The present investigation of ontogenetic processes was relevant to expand our understanding of floral evolution in the genus Mimosa and shed light on the unstable merism in the mimosoid clade.

Micromorphology of epicuticular waxes in genus Mimosa (Fabaceae)

Epicuticular waxes crystallize on the foliar surface with different morphologies, which can be taxonomically relevant features in many taxa. Their morphological analysis was based on scanning electron microscopy (SEM) images on herbarium specimens of selected sections of Mimosa. The present work is the first detailed description and classification of the epidermal micromorphology in the genus Mimosa, focusing on section Calothamnos and Mimosa series Mimosa, subseries Dolentes and Brevipedes. We also describe different wax crystallization morphologies present in these taxa, identifying three different crystallization types: film, plates, and platelets. Novel epidermal micromorphologies have been described, such as papillae in M. lepidorepens. Results allow grouping taxa of the studied sections, contributing to clarifying their taxonomy. SEM images of epicuticular waxes and leaf surfaces could be a new tool for performing a new taxonomic treatment of section Mimosa subser. Dolentes and subser. Brevipedes, and section Calothamnos.

Antioxidant, anti-inflammatory and analgesic activity of Mimosa acutistipula (Mart.) Benth

Ethnopharmacological relevanceMedicinal plants belonging to the genus Mimosa, such as Mimosa tenuiflora, M. caesalpinifolia, and M. verrucosa are known for their popular use for asthma, bronchitis and fever. Ethnopharmacological studies report that Mimosa acutistipula is used to treat alopecia and pharyngitis, conditions that can be related to oxidative stress, inflammatory processes and painful limitations. However, there is no studies on its efficacy and mechanism of action. Aim of the studyTo elucidate the antioxidant, anti-inflammatory, analgesic and antipyretic activity of M. acutistipula leaves. Materials and methodsPhytochemical profile of M. acutistipula extracts was evaluated by several reaction-specific methods. Secondary metabolites such as tannins, phenols and flavonoids were quantified with colorimetric assays. In vitro antioxidant potential was evaluated using DPPH and ABTS + as free radical scavenging tests, FRAP and phosphomolybdenum as oxide-reduction assays, and anti-hemolytic for lipid peroxidation evaluation. In vivo anti-inflammatory evaluation was performed by paw edema, and peritonitis induced by carrageenan. Analgesic effect and its possible mechanisms were determined by acetic acid–induced abdominal writhing and the formalin test. Antipyretic activity was evaluated by yeast-induced fever. ResultsCyclohexane, chloroform, ethyl acetate and methanol extracts of leaves had presence of tannins, flavonoids, phenol, alkaloids, terpenes (except methanolic extract), and saponins (only for methanolic and chloroformic extracts). In phenols, flavonoids and tannins quantification, methanolic and ethyl acetate extract had higher amounts of this phytocompounds. Ethyl acetate extract, due to its more expressive quantity of phenols and flavonoids, was chosen for carrying out the in vivo tests. Due to the relationship between oxidative stress and inflammation, antioxidant tests were performed, showing that ethyl acetate extract had a high total antioxidant activity (70.18%), moderate activity in DPPH radical scavenging, and a moderate ABTS + radical inhibition (33.61%), and FRAP assay (112.32 μg Fe2+/g). M. acutistipula showed anti-inflammatory activity, with 54.43% of reduction in paw edema (50 mg/kg) when compared to the vehicle. In peritonitis test, a reduction in the concentration of NO could be seen, which is highly involved in the anti-inflammatory activity and is responsible for the increase in permeability. In the analgesic evaluation, most significant results in writhing test were seen at 100 mg/kg, with a 34.7% reduction of writhing. A dual mechanism of action was confirmed with the formalin test, both neurogenic and inflammatory pain were reduced, with a mechanism via opioid route. In the antipyretic test, results were significantly decreased at all concentrations tested. ConclusionM. acutistipula leaves ethyl acetate extract showed expressive concentrations of phenolic compounds and antioxidant activity. It also exhibited anti-inflammatory and analgesic activity, besides its antipyretic effect. Thus, these results provide information regarding its popular use and might help future therapeutics involving this specimen.

Flavonoids from green propolis of the Northeastern Brazilian Caatinga Mimosa tenuiflora (Willd.) Poir.: A chemotaxonomic aspect

The phytochemical study of the hydroethanolic extract of green propolis produced by Apis mellifera in the Northeastern Brazilian Caatinga from Mimosa tenuiflora led to the isolation of sixteen flavonoids, including eleven flavonols 1–11, four flavanones 12–15, and one prenylated flavanone 16. It is the first time they were isolated from the green propolis of Caatinga M. tenuiflora. Flavonols 2–3, and 5–11, and flavanones 14–16 were first isolated from the genus Mimosa related materials, as well as ermanin (2), axillarin (5), eriodictyol 5-O-methyl ether (13), and 5,4′-dihydroxy-6,7-dimethoxyflavanone (14) have never been observed in the family Fabaceae related materials before. HPLC analysis of the hydroalcoholic extracts confirmed M. tenuiflora as the primary botanical source of Caatinga green propolis. Chemotaxonomic significance is discussed in detail.

Phytochemistry and Diverse Pharmacology of Genus Mimosa: A Review.

The genus Mimosa belongs to the Fabaceae family and comprises almost 400 species of herbs, shrubs and ornamental trees. The genus Mimosa is found all over the tropics and subtropics of Asia, Africa, South America, North America and Australia. Traditionally, this genus has been popular for the treatment of jaundice, diarrhea, fever, toothache, wound healing, asthma, leprosy, vaginal and urinary complaints, skin diseases, piles, gastrointestinal disorders, small pox, hepatitis, tumor, HIV, ulcers and ringworm. The review covered literature available from 1959 to 2020 collected from books, scientific journals and electronic searches, such as Science Direct, Web of Science and Google scholar. Various keywords, such as Mimosa, secondary metabolites, medicines, phytochemicals and pharmacological values, were used for the data search. The Mimosa species are acknowledged to be an essential source of secondary metabolites with a wide-ranging biological functions, and up until now, 145 compounds have been isolated from this genus. Pharmacological studies showed that isolated compounds possess significant potential, such as antiprotozoal, antimicrobial, antiviral, antioxidant, and antiproliferative as well as cytotoxic activities. Alkaloids, chalcones, flavonoids, indoles, terpenes, terpenoids, saponins, steroids, amino acids, glycosides, flavanols, phenols, lignoids, polysaccharides, lignins, salts and fatty esters have been isolated from this genus. This review focused on the medicinal aspects of the Mimosa species and may provide a comprehensive understanding of the prospective of this genus as a foundation of medicine, supplement and nourishment. The plants of this genus could be a potential source of medicines in the near future.

Pharmacognostical studies on whole plant of Mimosa pudica L

Background: Mimosa pudica is a creeping, diffuse, prickly undershrub of genus mimosa, native to tropical America which is also scattered along tropical and subtropical parts of India. It is well known as a sensitive plant, shame plant, touch-me-not, humble plant, shyness princess, and sleeping plant by virtue of rapid leaf movements in response to touch. Aim: The intention of this research was to investigate the morphological, micro anatomical, powder microscopy, proximate, and phytochemical analysis in whole plant of M. pudica. Materials and Methods: The investigation on macroscopy, microscopy, and physiochemical and phytochemical analyses were implemented using standard methods. Results: This study divulged unique macroscopical and anatomical characters present in the whole plant of M. pudica. The powder microscopy revealed the presence of trichomes, paracytic stomata, starch grains, prismatic crystals, mucilage, and brownish content. The quantitative microscopy performed in epidermal peelings of leaf quantified the epidermal number, stomatal number, stomatal index, and palisade ratio which determine its quality and purity. The proximate analysis performed was within the specific limits. The phytochemical analysis identifies different phytoconstituents in n-hexane and ethyl acetate extract. Further quantitative estimation disclosed that the total quercetin equivalent in 1 g of ethyl acetate extract of M. pudica was to be 13.39 mg and 27.5 mg of total β-sitosterol equivalent in n-hexane extract of M. pudica. Conclusion: This research concludes the assessment in whole plant of M. pudica by pharmacognostical, physiochemical, and phytochemical estimation for its identification and confirmation of species epithet from adulterated, substituted, or similar distant group species such as Albizia julibrissin, Acacia dealbata, Neptunia gracilis, and Mimosa tenuiflora.

Comparative Floral Micromorphology in Mimosa sect. Calothamnos (Fabaceae)

The genus Mimosa L. is well known for its high morphological variability and the presence of taxonomic complexes—groups of taxa that are not adequately circumscribed and are therefore in continuous revision. For this study, we analyzed flowers from 28 different taxa in Mimosa sect. Calothamnos Barneby and five vegetatively similar taxa from Mimosa sect. Mimosa. We observed three calyx shapes and four (glabrous or pubescent) calyx border types, as well as describe glandular trichomes on the calyx border for the first time in section Calothamnos. While the corolla exhibits only two shape types, trichomes on the corolla are much more diverse, as we found one simple and 11 branched trichome types in diverse orientations and dispositions. Given the taxonomic value of trichomes and profuse terminology in different families, we focused on the detailed description of their micromorphology, type, and shape, finding morphological differences between trichome types, which is an easy way to adequately compare them between even unrelated taxa. Our results using trichome types on the corolla are consistent with the original differentiation of sections Calothamnos and Mimosa. Flower micromorphology also provides characters to distinguish species, groups of species, and varieties within section Calothamnos and could be useful in a future taxonomic treatment of the section. We also found that some floral features, such as inflorescence color and stamen fusion, are associated with the characters used in this study.

A Comprehensive Review of the Ethnotraditional Uses and Biological and Pharmacological Potential of the Genus Mimosa.

The Mimosa genus belongs to the Fabaceae family of legumes and consists of about 400 species distributed all over the world. The growth forms of plants belonging to the Mimosa genus range from herbs to trees. Several species of this genus play important roles in folk medicine. In this review, we aimed to present the current knowledge of the ethnogeographical distribution, ethnotraditional uses, nutritional values, pharmaceutical potential, and toxicity of the genus Mimosa to facilitate the exploitation of its therapeutic potential for the treatment of human ailments. The present paper consists of a systematic overview of the scientific literature relating to the genus Mimosa published between 1931 and 2020, which was achieved by consulting various databases (Science Direct, Francis and Taylor, Scopus, Google Scholar, PubMed, SciELO, Web of Science, SciFinder, Wiley, Springer, Google, The Plant Database). More than 160 research articles were included in this review regarding the Mimosa genus. Mimosa species are nutritionally very important and several species are used as feed for different varieties of chickens. Studies regarding their biological potential have shown that species of the Mimosa genus have promising pharmacological properties, including antimicrobial, antioxidant, anticancer, antidiabetic, wound-healing, hypolipidemic, anti-inflammatory, hepatoprotective, antinociceptive, antiepileptic, neuropharmacological, toxicological, antiallergic, antihyperurisemic, larvicidal, antiparasitic, molluscicidal, antimutagenic, genotoxic, teratogenic, antispasmolytic, antiviral, and antivenom activities. The findings regarding the genus Mimosa suggest that this genus could be the future of the medicinal industry for the treatment of various diseases, although in the future more research should be carried out to explore its ethnopharmacological, toxicological, and nutritional attributes.

Stomatal micromorphology in a complex of Mimosa section Mimosa (Fabaceae).

The genus Mimosa Linnaeus (Leguminosae) comprises more than 530 species, being one of the most diversified genera in the family. A vast morphologic variability has been described at all infrageneric levels. Considering stomata description, a very low proportion of species have been studied in the genus, and the description was limited to stomata types, but not to variation in the disposition of subsidiary cells. Here we analyze type, length, and distribution of stomatic complexes in 19 taxa of Mimosa subseries Dolentes and subseries Brevipedes, a high variability taxonomic complex, as well as their density on both foliar faces and epidermic pavement cell morphology. We found four different stomatal types, 2 distribution types, and 3 epidermic pavement cell shapes. Some of these features are taxonomically relevant at infraspecific levels, since it adds important information for the separation of the taxa, but also questions supraspecific taxonomic groups of previous proposals of the genus. We also hypothesized about the origin of the variation of some stomata features in relation to ecological and ploidy-level variability in this complex.

A New Species of Mimosa L. ser. Bipinnatae DC. (Leguminosae) from the Cerrado: Taxonomic and Phylogenetic Insights.

Mimosa carolina (Leguminosae), a new species from the Parque Nacional Chapada das Mesas, located in the northern limit of the Brazilian Cerrado, is described and illustrated. In addition, a phylogenetic reconstruction was performed to recover the position of this species in relation to the main clades of the genus Mimosa. This new species is assigned to sect. Habbasia ser. Bipinnatae and exhibits relevant morphological differences with all described species of this series, most notably the prostate habit, glabrous stems, and absence of internal spicules. Our results indicate that this new entity is clearly nested in a strongly supported clade with other striated-corolla species of ser. Bipinnatae. Therefore, ser. Bipinnatae appears to be monophyletic, and a morphologically and ecologically cohesive group within Mimosa. An updated identification key for this series is provided.

Cryptic diversity of the genus Beauveria with a new species from Thailand

Thailand has rich natural resources and diverse ecosystems. From our surveys of entomopathogenic fungi in Thailand over the last decade, 66 Beauveria strains in BIOTEC Culture Collection (BCC) were studied to account for the diversity of this genus in Thailand. Examination of morphological characteristics from various media and phylogenetic analyses based on partial sequence of ITS, TEF, RBP1, RPB2, and the nuclear intergenic region Bloc, were realized. Among the strains from Thailand, we described here a new species, namely B. mimosiformis sp. nov., isolated from Coleoptera larva in the North of Thailand. This new species has a unique characteristic of phialides and conidia forming an ensemble similar to plant leaves of the genus Mimosa; it has pale yellow to light yellow stromata, cylindrical with rounded apices or oblong conidia, cylindrical part-ascospores. We also found a teleomorph linked to B. asiatica and documented new hosts (Lepidoptera larva and adult beetle) of B. gryllotalpidicola, as well as reported B. malawiensis for the first time in Thailand. Beside those species, B. bassiana and B. loeiensis were also identified, adding up to six species from Thailand. Through molecular phylogenetic analyses, we revealed (1) diverging lineages within B. asiatica and B. bassiana which, despite lack of support to be erected as any higher taxonomical unit, demonstrated complex intra-specific molecular diversity undergoing differentiation and (2) ambiguous relations between certain known species, particularly for B. majiangensis that we synonymized as B. asiatica.

<p><strong>Comparative wood anatomy of eight tree species of <em>Mimosa</em> sect. <em>Batocaulon</em> (Leguminosae) distributed in Mexico and their taxonomic implications</strong></p>

The great diversity of the genus Mimosa and the difficulty in the circumscription of its species and varieties based on morphology have encouraged the search for characters in other sources of evidence such as wood anatomy, which provides characters of taxonomic importance. The main objective of this study was to identify characters with taxonomic value for Mimosa; we studied the wood anatomy of eight tree species in Mimosa sect. Batocaulon from Mexico: Mimosa acantholoba, M. bahamensis, M. benthamii, M. hexandra, M. leucaenoides, M. tejupilcana, M. tenuiflora, and M. texana belonging to eight series: Acantholobae, Bahamenses, Distachyae, Bimucronatae, Leucaenoideae, Plurijugae, Leiocarpae and Boreales, respectively. One stem fragment (80 cm in length) was collected at 80 cm above soil height, from three plants per species. Twenty-five measurements were taken per individual for 15 anatomical characters. Three species have ring-porous wood and five species have diffuse-porous wood; the species differ in colour, figure, in the prevalence of a certain type of axial parenchyma, in the tangential diameter of the earlywood vessels, in the number of vessels connected by confluent-aliform parenchyma, in the number of series of rays and in the presence or absence of crystal sand in the ray cells. These characters have taxonomic value at species level, but not at series level. At the section level, the presence of homocellular rays distinguished Batocaulon from other sections of the genus. Based on these results, we produced a wood anatomical identification key to the eight studied species.

Genetic and morphological diversity and population structure of a polyploid complex of Mimosa (Leguminosae)

Evolutionary processes in plants such as hybridization and polyploidy are relevant to speciation and little studied in subtropical South America. In subtropical South America, the genus Mimosa is highly diverse, comprising 30% of polyploid species. The origin and genetic and morphological structure of polyploids in Mimosa are only very recently investigated, as well as their relevance to speciation, morphological variation, and distribution. Mimosa subser. Dolentes–Brevipedes, a taxonomic complex from that region, exhibits polyploidy, with specific and infraspecific taxa confusedly circumscribed. Studies of its population biology would facilitate the elucidation of evolutionary processes in Mimosa and resolution of taxonomic conflicts. We performed a multidisciplinary study of this complex, analysing seven populations and 87 individuals by means of morphometry, and AFLP fingerprinting throughout its area of distribution. Five populations included several taxa and intermediate individuals. Morphometric analyses revealed three clusters, distinguished mainly by leaf morphology and inflorescence. One population was tetraploid, one was tetraploid/octoploid and the rest octoploid. Genetic differentiation was high (PhiPT = 0.277) and expected heterozygosity was moderate (He = 0.190; H = 0.271). Multivariate molecular analyses revealed genetic divergence between highland and lowland grasslands. Structural genetic analyses revealed three clusters: two mixed, distinctly predominant in lowland/highland grasslands; another, exclusively from Mercedes. Molecular analysis of variance showed significant differences between highland/lowland grasslands and cytotypes. Cytotypes and populations differed partially by morphology. Tetraploids were morphologically similar to the sympatric octoploids, showing similar genetic structure and gene flow; furthermore, tetraploids are involved in origin of these higher polyploids. The systematics of this complex requires revision: subseries Dolentes and some Brevipedes species could be considered as one subseries. Admixture of genetic clusters and intermediates can be explained by hybridization and introgression. A marginal population differed from the others by morphology and genetics thus suggesting incipient speciation at the geographic edges of this complex.

Temporal variation in production and nutritional value of pollen used in the diet of Apis mellifera L. in a seasonal semideciduous forest

The flora of mountain formations in the Caatinga biome is composed predominantly by semi-deciduous species with representatives of both Atlantic and Amazon forest. Information on the potential for bee pollen production of these species is limited. In this study we evaluated the potential of production, the temporal variation, the botanical origin and the nutritional value of bee pollen produced in a seasonal semideciduous forest in northeastern Brazil. We identified a total of 252 flowering plant species throughout the year. The diet of Apis mellifera consisted of 74 pollen types distributed in 58 genera and 27 families. We identified two production peaks of bee pollen, the highest occurring in the rainy season. Nutritional value considering crude protein, carbohydrates, lipids and mineral matter changed over the study period, with influence of rainfall on the dry matter level. Some taxonomic groups of plants showed a strong relationship with nutrients, suggesting that although the diet of A. mellifera is broadly diversified, this species devoted most of its pollen foraging effort on the genus Mimosa and the palm tree species of Attalea speciosa. The results show that the seasonal semideciduous forest of the mountain range in the Northeast Brazil presents plant species: Mimosa caesalpiniifolia, Baccharis trinervis, Mimosa tenuiflora Myracrodruom urundeuva, Cecropia pachystachya, Attalea speciosa, with high nutritional level and potential for the pollen production.

Comparative study of pollen morphology and exine ultrastructure in tetrads, octads and polyads of the genus Mimosa (Leguminosae)

ABSTRACTThis is the first study of exine ultrastructure to be performed in five endemic Mexican Mimosa taxa (M. pringlei var. pringlei, M. calcicola, M. spirocarpa, M. caerulea and M. sousae), one occurring in Mexico and Central America (M. occidentalis), one widely distributed throughout the neotropics (M. setosa var. paludosa), and two in South America (M. irrigua and M. daleoides). Mimosa pollen grains are associated in polyads (12 grains), octads and tetrads. Polyads and octads in members of the basal clade of Mimosa phylogeny (sect. Mimadenia) evince the affinity of Mimosa with Piptadenia. Octads are retained in sect. Batocaulon and tetrads are evolved in this section. More recent clades (sect. Habbasia, Mimosa and Calothamnos) only show tetrads varying in size and shape. Polyads show greater variation in the exine layers, with a bistratified granular structure. Octads display a columellar-granular infratectal structure while tetrads in sect. Mimosa exhibit a less variable exine with a granular infratectal structure.

Lectotipificaciones en Mimosa (Leguminosae) del sur de Sudamérica

Se procedió a realizar la lectotipificación de tres especímenes del género Mimosa L. que crecen en Argentina: M. obstrigosa Burkart, M. tandilensis Speg. y M. callosa var. longiracemosa Burkart.Se describe el procedimiento para la elección de los lectotipos.

Mimosa chacoënsis (Leguminosae), nueva cita para la flora argentina.

Mimosa chacoënsis, perteneciente a la sección Habbasia serie Rojasianae del género Mimosa, es citada por primera vez para la Argentina, en la provincia de Formosa. Esta especie, endémica de la ecorregión del Chaco Seco, previamente había sido registrada sólo para Bolivia y Paraguay. Como resultado de este trabajo se eleva a 56 el número de especies conocidas de Mimosa para la Flora Argentina. Se presenta para esta especie una descripción morfológica detallada y observaciones, una ilustración, un mapa de distribución y una discusión de la ecología de la especie. Asimismo, se incluye una clave de identificación de las especies de Mimosa sección Habbasia de la Argentina.

Anatomia da madeira de Mimosa catharinensis Burkart (Leguminosae – Mimosoideae)

Mimosa catharinensis Burkart é um arbusto lianescente, ocorrendo apenas em duas áreas restritas de restinga no leste de Santa Catarina, Brasil. O presente trabalho apresenta a primeira descrição detalhada da anatomia da madeira de M. catharinensis, baseada em dados quantitativos. A descrição é ilustrada com fotomicrografias tomadas nos três planos anatômicos. Raios muito finos, parênquima paratraqueal, fibras libriformes não septadas, dimorfismo de vasos e poros tendendo a um arranjo diagonal foram encontrados. A estrutura anatômica da madeira é comparada com referências da literatura sobre a família Leguminosae e do gênero Mimosa, considerando seus aspectos filogenéticos, taxonômicos e ecológicos.