Image: Wikimedia Commons (See link for license)
River Moss Plant
Cladopus nipponica
カワゴケソウ
A highly specialized aquatic plant that clings to rock surfaces in fast-flowing streams. Its moss-like flat thallus adheres to rocks, growing submerged during high water and flowering when water levels drop. A Japanese endemic found in clear streams of Kyushu, Shikoku, and the Chugoku region.
Identification Points
- ✓Flat, moss-like green thallus adhering to rocks
- ✓The distinction between roots, stems, and leaves is indistinct
- ✓Small white flowers bloom simultaneously when water levels recede
Habitat
Rock surfaces in clear, fast-flowing streams
Season
April–June (flowers, when water levels drop)
Morphological TraitsAI-estimated, needs verification
Growth form
Herb
Habitat
Aquatic
Leaf arrangement
Alternate
Ovary position
Superior
Plant sex
Hermaphrodite
Phylogenetic Positionカワゴケソウ科 →
Phylogenetic Position
Angiosperms > Eudicots > Core eudicots > Malpighiales > Podostemaceae
Divergence Era
Paleogene (about 40–30 million years ago)
Evolution Notes
Podostemaceae has achieved highly specialized adaptation to fast-flowing water, with a unique morphology in which the distinction between roots, stems, and leaves is lost. Belonging to Malpighiales, it shows remarkable secondary reduction for aquatic life.
View on evolution timeline →Sources & References
AI-generated, needs verification