The genus Nolana (Solanaceae) comprises numerous species endemic to arid and semi-arid environments of the coastal areas of Chile and Peru and is characterized by a pentacarpellate ovary that develops into fibrous fruits knows as mericarps. This study aimed to comparatively analyse the anatomy and morphology of mericarps in 12 Chilean Nolana species, representing four phylogenetic clades, in order to identify interspecific patterns relevant to taxonomy and to discuss their ecological implications in terms of persistence, dispersal, and germination. Mericarps were analysed using light and scanning electron microscopy, as well as stereomicroscopy. In all species, the pericarp consisted of three main tissues: a single-layered exocarp, a mesocarp of variable thickness exhibiting the greatest interspecific variation, and a dense endocarp composed of a single layer of sclereids. Based on mesocarp structure, species could be grouped into three anatomical types, although these patterns did not correspond clearly with phylogenetic clades. Differences in mericarp size, shape, number of embryonic chambers, and tissue composition suggest functional links with dispersal modes and longevity in the soil seed bank. Although mericarp anatomy and morphology alone are insufficient for species-level identification, the characters described here provide complementary traits that may support taxonomic studies and improve understanding of adaptive strategies in arid environments.