LEAF MORPHOANATOMY OF PLANT SPECIES IN THE “PEDRA DOS SOARES” ROCKY OUTCROP, ESPÍRITO SANTO, BRAZIL

Abstract

Rock outcrops are characterized by extreme environmental conditions, such as high solar radiation, elevated temperatures, and low water availability, which directly influence the morphology, anatomy, and physiology of plant species. In Brazil, particularly in the state of Espírito Santo, these formations harbor high floristic diversity, although they remain poorly studied. This study analyzed five species occurring at Pedra dos Soares, in Ponto Belo, ES (Anthurium coriaceum, Cyrtopodium sp., Goeppertia makoyana, Mandevilla grazielae, and Philodendron edmundoi), aiming to compare their morphoanatomical and physiological traits in relation to solar incidence and temperature. Leaf and soil temperature, light intensity, leaf biometry, leaf anatomy, and photosynthetic pigment concentrations were evaluated. Mandevilla grazielae exhibited the highest leaf temperature (40.1°C) and light incidence (100.7 klux), indicating adaptations such as a thicker cuticle and higher stomatal density. Anthurium coriaceum showed lower temperature and light values, consistent with shade-adapted characteristics. Structural differences, including the presence of pulvini in A. coriaceum and G. makoyana, suggest mechanisms for regulating solar exposure. Variations in mesophyll organization and chlorophyll and carotenoid contents revealed distinct physiological strategies. These findings highlight the importance of morphoanatomical plasticity for plant survival under the heterogeneous and stressful conditions of rocky outcrops.