Marchantia polymorpha has a flat, branching form. Thalli are dichotomously branched and exhibit apical growth. Smooth rhizoids penetrate the soil, while tuberculate rhizoids run horizontally along the surface of the plant. In sexual reproduction, antheridia and archegonia develop on separate plant bodies and are borne on stalked antheridiophores and archegoniophores, respectively.
Fertilization takes place prior to elongation of the stalk, and a sporophyte is formed.
Vegetative reproduction may occur as a result of fragmentation or gemma cup production. In fragmentation, new plants are formed when older plant parts die at the fork of a branch of a thallus. Gametophytes produce propagative structures called gemma cups. Each gemma gives rise to numerous gemmae that are released when the cup fills with water.