The Notothyladaceae is the only family of hornworts in the order Notothyladales.
Description
Plants in the Notothyladaceae grow as a solid, flattened green structure (thallus) without internal air spaces, unlike some other hornwort families that have cavities within their tissues. Their reproductive structures include male organs (antheridia) that develop in small chambers within the thallus, with each chamber typically containing between two and eight antheridia. The spore-producing structures may or may not have tiny pores (stomata) on their surface. The spores range in colour from yellow to blackish and often have a distinctive band (equatorial girdle) around their middle. Within the cells, the chloroplasts (structures responsible for photosynthesis) may or may not contain a central protein body called a pyrenoid.
