Morphoanatomical and histochemical characterization of Larreas species (Zygophyllaceae) from Northwestern of Argentina

MERCADO MARÍA INÉS,; ISLA MARIA

Brasilian journal of pharmacognosy

Sociedade Brasileira de Farmacognosia

Año: 2018 vol. 28 p. 393 - 401

0102-695X

Larrea divaricata, L. cuneifolia and L. nitida are evergreen xerophytic shrubs occurring in Northwestern Argentina used in traditional medicine to treat fungal and bacterial infections and as antioxidant, anti-inflammatory and inmunomodulatory. The aim of this work was to characterize the morphology, anatomy and histochemistry of the vegetative organs of these Larrea species by light and scanning electron microscopy in order to provide supporting data for their correct identification and to determine the site of synthesis and accumulation of its main active compounds. The shape, number and percentage of coalescence of leaflets, presence or absence of mucron and rachis and the stipules shape represented the main botanical differences between the studied Larrea species. Anatomically The three species presented amphystomatic leaves, with thick resinous slightly striated cuticle with resinous deposits, polygonal epidermal cells with straight anticlinal walls, ciclocytic, brachy-paracytic and paracytic stomatal types, non-glandular trichomes, isolateral mesophyll, however the position and abundance of the sclerenchyma at the mid vein and petiole transection allows the differentiation of the three species been more abundant in L. cuneifolia. Secondary phloem and parenchyma cells presented abundant calcium oxalate druses and solitary rhomboidal crystals. Epidermal cells and cuticle layer of leaflets and stipules of the three species presented amber resin deposits and content which stained positively for polysaccharides, phenolic compounds, flavonoids and tannins, while mesophyll palisade cells showed small refracting droplets stained positively for lipophilic substances.