Foliar morphology of Polylepis australis Bitter (Rosaceae) in Taff del Valle, Tucuman, Argentina. Some regards about the complex of flavonoids

Abstract

The species Polylepis australis Bitter «queñoa» is a tree of 3-6 (8) m high which colonizes between 1,680 and 2,800 m over sea level. This range of height represents the tree altitude level in the high mountains. The material has been collected in Tafí del Valle (2,000 m over sea level). The external-internal structures of the leaves have been analized using the following techniques: magnifying glass, O.M., T.E.M. and S.E.M. The leaves have been stained with «hematoxilin-eosin» and «staining-fast green». The anatomical features of leaves like lenght and width, stomatic density, and thickness of tissues, have been measured. Compound and imparipinnats leaves with 5-7 foliols have been registered, as well as, in transversal cuttings, dorsiventral and hypostomatic leaves with abaxid and adaxid single-layered epidermis have been noted. Three types of appendix skins have been identified under epidermis: the palisade (2-3 layers), spongy mesophyll uniform stomas, and anomocit stomas. These structural characteristics are supposed to be a behavior of adaptation to the mesomorphic environment. The chromatographic profile of flavonoid contents have been analized and their results discussed.