''Ceratophyllum muricatum'', commonly known as the prickly hornwort, is a species of ''

Ceratophyllum ''Ceratophyllum'' is a cosmopolitan distribution, cosmopolitan genus of flowering plants commonly found in ponds, marshes, and quiet streams in tropical and in temperate regions. It is the only extant taxon, extant genus in the family Ceratophyll ...

'' native to much of Europe, Asia, Africa, and the Americas. In the US it has been observed specifically in the states of Florida, Georgia and North Carolina. It has also been observed in Cuba and Jamaica. This species is only able to thrive in inland areas, however, due to being a low-salinity tolerant species. It is rarely observed in coastal tropical areas for these reasons. One fossil subspecies, ''Ceratophyllum mericatum incertum'' has been named from

Early Eocene In the geologic timescale the Ypresian is the oldest age (geology), age or lowest stage (stratigraphy), stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by th ...

fossils found in the

Green River Formation The Green River Formation is an Eocene geologic formation that records the sedimentation in a group of intermountain lakes in three basins along the present-day Green River (Colorado River), Green River in Colorado, Wyoming, and Utah. The sedimen ...

and the Wilcox Group.

References

{{Taxonbar, from=Q15482317 muricatum Freshwater plants Flora of Europe Flora of Asia Flora of Africa