Question

Why hornworts are so called ?

Answer 1

The English word "wort" means "small plant" and it turns up in names such as Pennywort and Bladderwort. Thus a hornwort is a "small, horned plant".

Answer 2

It is called hornwort because it has small thorn like structures which is the saprophyte. Another trait is that most of them develop mucilage filled cavities. These cavities sometimes attacked by cyanobacteria and starts growing inside them. Due to the presence of the cyanobacteria hornwort has a distinct blue-green color.