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Japanese Yam
Dioscorea japonica
ヤマノイモ
A perennial twining herb native to mountain fields. An elongated tuberous root extends vertically underground and is edible. Bulbils (mukago) form in leaf axils, and the heart-shaped leaves are opposite to whorled.
Identification Points
- ✓Leaves elongated heart-shaped (sagittate), opposite to whorled
- ✓Bulbils (mukago) produced in leaf axils
- ✓Long cylindrical tuber underground
Habitat
Forest edges, grasslands, and roadsides in mountain fields
Season
August–September (flowers), October–November (bulbils)
Morphological TraitsAI-estimated, needs verification
Growth form
Vine
Leaf arrangement
Opposite
Leaf shape
Cordate
Venation
Palmate
Petal count
6 petals
Flower symmetry
Actinomorphic
Ovary position
Inferior
Compound type
Palmate
Phylogenetic Positionヤマノイモ科 →
Phylogenetic Position
Angiosperms > Monocots > Dioscoreales > Dioscoreaceae
Divergence Era
Late Cretaceous (ca. 90–80 Ma)
Evolution Notes
Dioscoreaceae is a distinctive monocot group that evolved a twining habit and underground storage organs, distributed widely from the tropics to temperate regions.
View on evolution timeline →Sources & References
AI-generated, needs verification