The morphology of the free-living gametophytic generation varies within Marchantiophyta. There are many forms of gametophyte ranging from thalloid to leafy, and large to small. The isodiametric cells of the gametophore contain trigones, chloroplasts, and typically have oil bodies. The oil bodies are true membrane-bound organelles that vary in size, shape, number, color, and chemical composition among species. When liverworts are dried (such as for storage in a Herbarium) the oil bodies degrade at varying rates over time. The function of oil bodies is currently unknown, but they may serve to deter herbivores or aid in protection from the cold or UV rays.