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Marsh Fern
Thelypteris palustris
ヒメシダ
A fern growing in wetlands and waterside areas across Japan. It forms colonies by extending slender creeping rhizomes. Fronds are bipinnately shallowly lobed and bright yellow-green. Known as an indicator species of wetland ecosystems.
Identification Points
- ✓Fronds bipinnately shallowly lobed, yellow-green
- ✓Basal basiscopic veins of adjacent pinnae converge in an X-pattern
- ✓Forms colonies in moist habitats
Habitat
Wetlands, rice paddy margins, and marshes
Season
Spring–autumn (fronds)
Morphological TraitsAI-estimated, needs verification
Growth form
Herb
Leaf dissection
Dissected
Leaf shape
Linear
Habitat
Wetland
Phylogenetic Positionヒメシダ科 →
Phylogenetic Position
Vascular plants > Polypodiophyta > Polypodiopsida > Polypodiales > Thelypteridaceae
Divergence Era
Cretaceous (ca. 90 million years ago–)
Evolution Notes
Thelypteridaceae is a fern group specialized for wetland environments; the vein anastomosis pattern (reticulate venation) is an evolutionary hallmark of this family.
View on evolution timeline →Sources & References
AI-generated, needs verification