Anthoceros is a genus of hornworts in the family Anthocerotaceae. The genus is global in its distribution. Its name means 'flower horn', and refers to the characteristic horn-shaped sporophytes that all hornworts produce. Pteris is a genus of about 280 species of ferns in the Pteridaceae subfamily of the Pteridaceae. They are native to tropical and subtropical regions of the world. Riccia is a genus of liverworts in the order Marchantiales. The plants are small. The plant body is a thallus that is not differentiated into root, stem, and leaf. Marchantia is a genus in the family Marchantiaceae of the order Marchantiales, a group of liverworts. These are simple plants without roots or vascular systems. It is called liverwort.