Seedling performance, allocation patterns and phenotypic plasticity of two sympatric hawthorn species and their natural hybrid

•Crataegus monogyna, C. rhipidophylla and their hybrid seedlings had similar performance.•C. rhipidophylla had shorter, more dense stems compared to C. monogyna, with the hybrid being intermediate.•The hybrid manifested a higher phenotypic plasticity relative to at least one of its parents in biomass allocation in response to water availability.•The “mosaic model” describes most accurately the hybrid zone of the studied taxa.