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Spiral Ginger
Costus speciosus
コスタス
A perennial herb native to Southeast Asia, found wild at forest edges in the Ryukyu Islands and cultivated in greenhouses and gardens as an ornamental. Its most distinctive feature is the spiral arrangement of leaves along the stem, earning it the name 'Spiral Ginger.'
Identification Points
- ✓Leaves arranged spirally along the stem
- ✓Erect stem bearing large white bracts and white flowers
- ✓Rhizome resembling ginger
Habitat
Forest edges of the Ryukyu Islands; greenhouses and gardens (cultivated)
Season
Summer–Autumn (flowers)
Morphological TraitsAI-estimated, needs verification
Growth form
Herb
Leaf arrangement
Alternate
Leaf type
Simple
Venation
Pinnate
Leaf margin
Entire
Petal count
6 petals
Leaf dissection
Undivided
Flower symmetry
Zygomorphic
Ovary position
Inferior
Plant sex
Hermaphrodite
Aromatic
None
Stamen count
3-4
Phylogenetic Positionコスタス科 →
Phylogenetic Position
Angiosperms > Monocots > Zingiberales > Costaceae
Divergence Era
Paleogene
Evolution Notes
Costaceae was formerly included in Zingiberaceae but separated under APG classification due to spiral leaf arrangement and a single petaloid stamen. It demonstrates evolutionary diversity within Zingiberales.
View on evolution timeline →Sources & References
AI-generated, needs verification