LEAF ANATOMICAL CHARACTERIZATION OF TWO ANTHURIUM SPECIES (ARACEAE) WITH A HIGH POTENTIAL FOR ORNAMENTAL PURPOSES

Anthurium bonplandii and A. plowmanii belong to the Araceae family, which have high potential for use as ornamental plants. They are native to Brazil, and their cultivation and sale may represent an alternative source of novelties to the national floriculture. The aim of this work was to understand the leaf anatomy of these plants. Fully expanded leaves of plants selected from the Embrapa Germplasm Bank of Ornamental Tropical Plants located in Fortaleza-CE were used. The leaves were subjected to sodium hypochlorite for analysis of the epidermis in paradermic order. For the cross section analysis, the leaves were fixed in FAA₅₀ (formaldehyde, acetic acid and alcohol), dehydrated in ethanol, subjected to pre-infiltration solution, infiltration solution and inserted in Leica historesin. The material was cut into semi-automatic microtome with a thickness of 10 μm and the sections were stained with Toluidine Blue for structural analysis. It was also made free hand cuts to materials fixed for histochemical analysis. Phloroglucinol acid was used for detection of lignin and phenolic compounds, Sudan III was used for detection of lipids, and Lugol was used for starch detection. The two species had similar anatomical features. Both have a uniseriate epidermis with paracytic stomata in abaxial face and are completely covered by a cuticle. The mesophyll consists of chlorenchyma. In A. bonplandii the vascular bundles are of the collateral type, completely surrounded by sclerenchyma. In the midrib and petiole, they are surrounded by parenchyma cells rich in starch. Idioblasts containing phenolic compounds and calcium oxalate crystals are also found. In A. plowmanii the parenchyma cells have fewer starch grains than A. bonplandii and there are no phenolic compounds idioblasts dispersed in the ground parenchyma. These features may help understand many aspects of this leaves, such as external appearance and adaptation to environmental conditions.