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Floating Fern
Salvinia natans
サンショウモ
A floating aquatic fern found in ponds and rice paddies. Leaves occur in groups of three: two floating leaves and one submerged leaf bearing sporocarps. The floating leaf surface has fine papillae that repel water.
Identification Points
- ✓Leaves in sets of 3: two floating and one submerged
- ✓Floating leaves are elliptic with fine papillae that repel water
- ✓A rootless floating fern (Salviniaceae, order Salviniales)
Habitat
Water surface of ponds, rice paddies, and reservoirs
Season
June–October (floating period)
Morphological TraitsAI-estimated, needs verification
Leaf shape
Round
Habitat
Aquatic
Phylogenetic Positionサンショウモ科 →
Phylogenetic Position
Vascular plants > Polypodiophyta > Polypodiopsida > Salviniales > Salviniaceae
Divergence Era
Cretaceous to Paleogene (ca. 80 million years ago–)
Evolution Notes
Salviniaceae, while true ferns, have highly advanced aquatic adaptations for floating on the water surface. They are heterosporous, producing two types of spores (megaspores and microspores).
View on evolution timeline →Sources & References
AI-generated, needs verification