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Sago Palmπ΄
Cycas revoluta
γ½γγ
A gymnosperm native to southern Kyushu and Okinawa. A 'living fossil' surviving from the age of dinosaurs. Pinnately compound leaves spiral at the top of a stout trunk. It is dioecious, producing male and female cones. The starch from the trunk was historically used as food.
Identification Points
- βTrunk is thick and columnar, covered with persistent leaf bases
- βLeaves are pinnately compound and coriaceous; leaflet margins strongly revolute
- βMale cones are cylindrical; female cones are globose bearing large seeds
Habitat
Coastal and rocky areas of southern Kyushu and Okinawa (native); cultivated widely
Season
Male cones: MayβJuly
Morphological TraitsAI-estimated, needs verification
Leaf arrangement
Alternate
Leaf type
Compound
Venation
Pinnate
Leaf margin
Entire
Leaf shape
Linear
Growth form
Tree
Evergreen/Deciduous
Evergreen
Petal fusion
No petals
Stipules
Absent
Ovary position
Superior
Plant sex
Dioecious
Compound type
Pinnate
Phylogenetic Positionγ½γγη§ β
Phylogenetic Position
Gymnosperms > Cycadopsida > Cycadales > Cycadaceae
Divergence Era
Paleozoic Permian to Mesozoic Triassic (approx. 280 million years ago onward)
Evolution Notes
Cycadaceae has existed for approximately 280 million years, representing an ancient gymnosperm lineage that covered the earth before angiosperms diversified. It retains the primitive fertilization method where flagellated sperm swim to reach the egg.
View on evolution timeline βSources & References
AI-generated, needs verification