Liverworts (Phylum Marchantiophyta) are very primitive, non-vascular land plants, persisting in very moist (but not aquatic) environments. Liverworts are flattened, ribbon-like leaves with a waxy cuticle, and are held to their substrate with single-celled rhizoids, or root-like structures. Liverworts have a gametophyte-dominant life cycle, meaning the entire plant is typically haploid throughout their lives (unlike nearly all other plants). Due to this life cycle, liverworts must be fertilized in order to reproduce. Once fertilized, they reproduce via spores.