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Sphenoclea
Sphenoclea zeylanica
スフェノクレア
An annual rice paddy weed native to tropical Asia and Africa, confirmed as naturalized in rice paddies of the Ryukyu Islands. It has erect stems with narrow leaves and dense spike-like inflorescences at the tips. Known worldwide as an invasive weed of tropical rice paddies.
Identification Points
- ✓Rice paddy weed with erect stems and alternate leaves
- ✓Dense cylindrical spike-like inflorescences at stem tips
- ✓Grows in rice paddies and wetlands
Habitat
Rice paddies and wetlands of the Ryukyu Islands (naturalized)
Season
Summer–Autumn (flowers)
Morphological TraitsAI-estimated, needs verification
Growth form
Herb
Leaf arrangement
Alternate
Habitat
Aquatic
Leaf type
Simple
Venation
Pinnate
Petal count
Many
Stipules
Absent
Leaf dissection
Undivided
Flower symmetry
Actinomorphic
Plant sex
Hermaphrodite
Latex
Absent
Stamen count
5
Phylogenetic Positionスフェノクレア科 →
Phylogenetic Position
Angiosperms > Eudicots > Core Eudicots > Campanulales > Sphenocleaceae
Divergence Era
Paleogene (ca. 45 million years ago)
Evolution Notes
Sphenocleaceae is a monotypic family in Solanales, having evolved highly specialized adaptation to rice paddy environments. Recognized as close to Campanulaceae under the APG system.
View on evolution timeline →Sources & References
AI-generated, needs verification