ABSTRACT Piper caldense C. DC., Piperaceae, commonly known as “pimenta-d’água”, “pimenta-darda” or “paguarandy” in Brazil, is a shrub that grows mainly in humid and shaded habitats. The present study investigates the anatomy of the leaves and stems of P. caldense by light and scanning electron microscopy in order to provide supporting data for correct identification of the species. The leaves are hypostomatic, have a 2-layered hypodermis, and posses pearl glands. The midrib shows a ‘U’-shaped stele comprised of about ten collateral vascular bundles. The main anatomical marker of the stem is the presence of a continuous sclerenchymatous sheath in the pith. Two forms of calcium oxalate crystals, namely crystal sand and raphides, are observed in this species.

ABSTRACT Baccharis belongs to the Asteraceae family and comprises a number of medicinal species. Baccharis brevifolia DC., B. microdonta DC., B. pauciflosculosa DC., and B. trilobata A.S. Oliveira & Marchiori, which are popularly known in Brazil as “vassouras” (“broom”), are all found in Southern Brazil. The anatomical features of the leaf and stem were investigated by employing the usual light and scanning electron microtechniques, as a means of differentiating the taxa. The following anatomical characteristics can be considered to be diagnostic: the occurrence and type of stomata, midrib, stem and crystal shapes, and the presence of the petiole.