Resumen
Quina (Strychnos pseudoquina A. St. Hil.). Loganiaceae, a native tree from the Brazilian savannah, is widely used in npopular medicine. In the present study, quina leaves of plants grown in glasshouse or at field conditions were anatomically and histochemically characterized. For the anatomical studies transverse sections taken from the middle third of leaves were stained with 0.05% toluidine blue, pH 4.0. Leaf samples were diaphanized and stained with 1% safranine to study the leaf surface. Phenolic compounds, lipids, starch, and alkaloids were analyzed by several histochemical methods. It was found in the quina leaves the stomata are present only in the abaxial surface and are paracytic. The typical epidermal cells are slightly sinuous and have few trycomas. Cuticle is thin in leaves of plants grown in greenhouse but thick in leaves of plants at field condition. The mesophyll is typically dorsiventral containing collateral vascular bundles. Phenolic compounds were found in the epidermal cells however no lipids, starch or alkaloids were found in any leaf tissue.