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Please cite this article in press as: de Almeida, V.P., et al. Comparative morphoanatomical analysis of Mikania species. Revista Brasileira de Farmacognosia (2016), http://dx. a b s t r a c tMikania belongs to the Asteraceae family and includes a wide range of promising pharmacological activities. Several species of Mikania, which is popularly known in Brazil as "guaco", occur in Southern Brazil and their external morphology is similar. The aim of this study was to investigate the morpho-anatomical characteristics of the leaf and stem of Mikania campanulata, Mikania cordifolia, Mikania glomerata, Mikania hastato-cordata, Mikania microptera and Mikania sessilifolia as a means of providing additional support for differentiating these taxa. The leaves and stems were investigated by employing scanning electron microscopy and light microscopy techniques. The morphological features of Mikania spp. leaves make it possible to differentiate between the species; nevertheless, when the plants were fragmented or pulverized the anatomical features of the leaves and stems supplied additional helpful data in this regard. The main anatomical characteristics were presence of hypodermis and lens shaped epidermal cells, set of trichomes; midrib, petiole and stem shape and vascular pattern; sclerenchymatous ring in the cortex, sclerenchymatous cells and secretory ducts in the pith.

This article enumerates the detailed anatomy of Cantinoa althaeifolia (Lamiaceae) illustrated with light and scanning electron microscopy images. The anatomical markers include the presence of branched nonglandular trichomes and capitate, peltate, and clavate types of glandular trichomes; prismatic crystals on the leaf and stem surfaces; and oil droplets in the leaf mesophyll. Histochemical tests and EDS analyses were performed in order to detect the composition of certain cells and their contents. The key findings of the present study can contribute to the taxonomy, species identification, and quality control of Cantinoa althaeifolia. K E Y W O R D S crystals, leaf anatomy, micromorphology, stem anatomy, trichomes

The aim of this study was to evaluate the chemical, antioxidant, and antimicrobial activity of the essential oils as well as the anatomy of the aerial parts from Baccharis aracatubaensis, Baccharis burchellii, and Baccharis organensis owing to the therapeutic potential of Baccharis. The volatile constituents were analyzed using GC/MS, the antioxidant activity was evaluated by oxygen radical absorbance capacity (ORAC FL ) and DPPH assays, and the antimicrobial activity by a microdilution technique. Of the 56 compounds identified, only seven (β-caryophyllene, γ-muurolene, bicyclogermacrene, β-germacrene, spathulenol, τ-muurolol, and α-cadinol) were common in the three specimens studied. Of these, γ-muurolene was found abundantly in B. aracatubaensis, while bicyclogermacrene was abundant in B. burchellii and B. organensis. The essential oils exhibited antioxidant activity in the ORAC FL (> 500.0 μmol TE g À 1 ) and DPPH assays. However, they did not exhibit any antimicrobial activity. Secretory ducts and flagelliform glandular trichomes were observed in the anatomical study of all the Baccharis species studied.

This study provides a comprehensive account of the various types of calcium oxalate crystals found in the genus Baccharis and assesses the exceptional value of crystal macropatterns for the taxonomy of the genus. The morphotype, occurrence, and chemical composition of the crystals found in the stems and leaves are studied. The 44 species included in this study were selected based on a broad phylogeny‐based sampling covering seven subgenera and 31 sections. These species were chosen to represent all the main phylogenetic lineages of Baccharis; thus, the sampling also represents a comprehensive coverage concerning evolutionary significance for such a large and environmentally and economically important plant group. The samples were analyzed by light microscopy, scanning electron microscopy (SEM), and energy‐dispersive x‐ray spectroscopy (EDS). Several morphotypes of crystals, including druses, crystal sand, styloids and prisms, were present. Based on their chemical composition, the crystals were classified as pure calcium oxalate, mixtures of oxalates and sulfates, and mixtures of oxalates, sulfates, and silica. The crystal macropatterns observed in this study aid in species identification and provide novel data for the taxonomy of Baccharis. Research Highlights Most species of Baccharis have a specific crystalline pattern. Each species produces a crystal morphotype or a set of morphotypes specific to it. The crystals observed are formed by calcium oxalate.

This study provides a comprehensive account of the various types of calcium oxalate crystals found in the genus Baccharis and assesses the exceptional value of crystal macropatterns for the taxonomy of the genus. The morphotype, occurrence and chemical composition of the crystals found in the stems and leaves are studied. The 44 species included in this study were selected based on a broad phylogeny-based sampling covering seven subgenera and 31 sections. These species were chosen to represent all the main phylogenetic lineages of Baccharis; thus, the sampling also represents a comprehensive coverage concerning evolutionary significance for such a large and environmentally and economically important plant group. The samples were analyzed by light microscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). Several morphotypes of crystals, including druses, crystal sand, styloids and prisms, were present. Based on their chemical composition, the crystals were classified as pure calcium oxalate, mixtures of oxalates and sulfates, and mixtures of oxalates, sulfates and silica. The crystal macropatterns observed in this study aid in the species identification and provide novel data for the taxonomy of Baccharis.