Image: Wikimedia Commons (See link for license)
Hornwort family
Ceratophyllaceae
キンギョモ科
A family of aquatic plants widely distributed in freshwater habitats worldwide. A small family comprising only a few species such as hornwort (Ceratophyllum demersum). Lacks roots entirely and lives fully submerged in water. Occupies a unique phylogenetic position among angiosperms (outside the eudicots).
Key Characteristics
- ●Completely lacks roots (rootless aquatic plant)
- ●Leaves are whorled, filamentous with dichotomously forked tips
- ●Flowers are unisexual, lacking perianth, extremely simple
- ●Fully submerged plant with hydrophilous (water) pollination
- ●Buoyant internodes allow floating in water
Morphological Traits
A family may include species with different trait values — multiple values indicate the range within the family.
Leaf arrangement
Whorled
Leaf type
Simple / Compound
Venation
Pinnate
Leaf margin
Entire
Growth form
Herb
Evergreen/Deciduous
Deciduous
Leaf dissection
Dissected
Stipules
Absent
Flower symmetry
Actinomorphic
Petal count
Many
Petal fusion
Free
Ovary position
Superior
Plant sex
Monoecious
Phylogenetic Position
Angiosperms > Ceratophyllales > Ceratophyllaceae (positioned near the base of eudicots)
Divergence Era
Early to Mid-Cretaceous (about 120–100 million years ago)
Representative Genera
Related Evolution Events
- ・Evolution toward fully submerged, free-floating life through complete loss of roots
- ・Phylogenetic isolation as one of the earliest diverging lineages among angiosperms
Plants in Hornwort family on this site
AI-generated, needs verification