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Extrafloral glands in Passifloraceae species have aroused the interest of many researchers because of their wide morphological diversity. The present work analyzed the foliar glands on 34 species of Passiflora from samples containing glands in the petiole and foliar blade fixed in 50% solution of formaldehyde-ethanol-acetic acid and stored in a 70% ethanol solution. For anatomical analyses, part of the material was embedded in Paraplast, longitudinally sectioned and double stained with safranin and astra blue. Scanning electron microscopy analysis was also carried out. To analyze the presence of sugars in the secretion of foliar glands, a glucose strip test was used. Based on the results of morphological, anatomical and glucose strip tests, the foliar secretory glands in Passiflora can be grouped into two categories: Type I glands, defined as nectaries, can be elevated or flattened, and can have a sugar content high enough to be detected by the glucose strip test analysis. Type II glands are elevated and did not show a positive reaction to the glucose strip test. From an anatomical viewpoint, glands characterized as extrafloral nectaries show a multistratified secretory epidermis, typically followed by two flat layers of nectariferous parenchyma with dense content. Internal to these layers, vascular bundles are immersed in the subsecretory parenchyma and terminate in phloem cells. On the other hand, type II glands show a single layer of elongated secretory epidermal cells. Internal to this single layer, parenchyma and vascular tissue with both phloem and xylem elements can be observed. The analyzed species show a wide diversity of gland shape and distribution, and the combined analysis of morphology, anatomy and preliminary tests for the presence of glucose in the exudate in different Passiflora subgenera suggests the occurrence of two categories of glands: nectaries and resin glands.

Contamination of medicinal plants with heavy metals as Pb and Cd can affect the growth and the essential oil production of the plants and represent a risk to those who consume as medicine. This study aimed to evaluate the effects of absorption and localization of Pb and Cd on growth, ultrastructural aspects of leaves and essential oil yield and composition of Mentha arvensis,applied on the soil with increasing concentrations (8, 16, 32, 64 and 128mg kg -1 (8, 16, 32, 64 and 128mg kg -1

RESUMO -(Efeitos do cádmio na anatomia e na fotossíntese de duas macrófitas aquáticas). As macrófitas aquáticas vêm sendo usadas no monitoramento de águas poluídas por metais pesados, dessa forma, avaliou-se a capacidade fitorremediadora de Alternanthera philoxeroides (Mart.) Palavras-chave: Alternanthera philoxeroides, fluorescência da clorofila, metal pesado, Polygonum ferrugineumABSTRACT -(Effects of cadmium on the anatomy and photosynthesis of two aquatic macrophytes). Aquatic macrophytes have been used to monitor waters polluted by heavy metals. The phytoremediation capacity of Alternanthera philoxeroides (Mart.) Griseb. (Amaranthaceae) and Polygonum ferrugineum Wedd. (Polygonaceae) was therefore evaluated. These two species were submitted to treatments of 0, 25 and 50 mg L -1 Cd in nutritive solution. Seven days after treatment application, leaf gas exchange and chlorophyll fluorescence were measured in mature and fully expanded leaves. Fragments of roots, shoots and leaves were fixed in FAA 70, embedded in historesin and cut with a rotating microtome, and the sections stained with 1% toluidine blue. The Cd content in plant biomass was determined using ICP-MS. In P. ferrugineum exposed to 25 and 50 mg L -1 Cd, an increase in the central leaf-vein-and root-aerenchyma lacunae was observed. Furthermore, in plants exposed to 50 mg L -1 Cd, an increase in leaf glandular trichomes and mesophyll compacting was observed. In the stem of A. philoxeroides exposed to 50 mg L -1 Cd, the nuclei of the cortex cells became elliptic, and at 25 and 50 mg L -1 Cd, the number of druses in the cells of the central leaf vein was reduced. Cd accumulation was higher in the roots, followed by the stem and leaves in A. philoxeroides. The net photosynthesis rate of P. ferrugineum was more affected by Cd than that of A. philoxeroides. There was no variation in photosystem II (Fv/Fm) activity between the two species and the Cd treatments. A. philoxeroides was more cadmium-tolerant than P. ferrugineum, which indicates its capacity for use in phytoremediation programs.