What is "hornwort"

Hornwort \Horn"wort`\, n. (Bot.) An aquatic plant ( Ceratophyllum), with finely divided leaves.

n. A bryophyte with a leafless thallus characterized by a dominant gametophyte stage of the life cycle and a sporophyte stage shaped like a horn.

1. n. any aquatic plant of the genus Ceratophyllum; forms submerged masses in ponds and slow-flowing streams

2. liverworts with slender hornlike 2-valved capsules

Hornworts are a group of non-vascular plants comprising the division Anthocerotophyta. The common name refers to the elongated horn-like structure, which is the sporophyte. As in mosses and liverworts, the flattened, green plant body of a hornwort is the gametophyte plant.

Hornworts may be found worldwide, though they tend to grow only in places that are damp or humid. Some species grow in large numbers as tiny weeds in the soil of gardens and cultivated fields. Large tropical and sub-tropical species of Dendroceros may be found growing on the bark of trees.