ABSTRACT
ABSTRACT Dysphania ambrosioides (L.) Mosyakin & Clemants (syn: Chenopodium ambrosoides L.), Amaranthaceae, popularly known as “mastruz”, is an herb widely used in Brazil as anthelmintic. To contribute to the knowledge about medicinal plants, a microscopic analysis was accomplished to describe the main anatomical characters of root, stem, petiole and leaf blade of D. ambrosioides and histochemical tests were performed on the leaf blade. Cross-sections were obtained, by hand, for microscopic analysis of root, stem, petiole and leaf blade; to the leaf blade were still made paradermal sections, scanning electron microscopy analysis, maceration and histochemical tests. The main characters useful in the identification of the plant were: anomalous secondary thickening in the root and stem; presence of idioblasts containing crystal sand in the root, stem, petiole and leaf blade; in these there are also idioblasts with druses; presence of non-glandular and glandular trichomes in the stem, petiole and leaf blade; stomata on the stem, petiole and leaf blade, identified in these as anomocytic and anisocytic; dorsiventral mesophyll and collateral vascular bundles. Maceration revealed that the vessel elements are helical type. Through the histochemical tests, it was evidenced the presence of lipophilic substances, essential oils, oleoresins, phenolic compounds, starch, lignin and calcium oxalate crystals. This work provides support to the quality control of the species.