Tree development in semiarid Yucatán climate is primarily determined by the configuration of the karst rather than characteristics of the overlaying thin soils (< 30 cm deep). In this study a description of the Yucatan karst features below the soil were described in order to evaluate their importance on tree root development. We described the stratigraphy and root distribution on a freshly exposed wall in a limestone quarry. Vegetation consisted of secondary deciduous forest. Our observations showed that some roots grow in rock cracks and crevices while others are able to grow through the matrix of certain kinds of rock. Even though all the types of rock were composed of calcium carbonate they varied with regard to density and porosity, suggesting differences in water holding capacity. We also found pockets of deep soil at different levels which contained roots. No roots were found close to the ground water table (10 m). Karstic features appear to have an important role on tree root development by providing them water and microsites in which grow.