Cycad family
Cycadaceae

Image: Wikimedia Commons (See link for license)

Cycad family🌴

Cycadaceae

ソテツ科

Share on X

One of the most ancient lineages among extant gymnosperms. Dioecious, characterized by large pinnately compound leaves and cones (female plants bear seeds directly). In Japan, a single species (Cycas revoluta) occurs naturally near coasts of the southwestern islands.

Key Characteristics

  • Dioecious
  • Large pinnately compound leaves densely spiraling at the trunk apex
  • Male cones erect and cylindrical; female plants bear seeds on large pinnate megasporophylls
  • Coralloid roots harboring symbiotic cyanobacteria for nitrogen fixation

Morphological Traits

A family may include species with different trait values — multiple values indicate the range within the family.

Leaf arrangement

Alternate

Leaf type

Compound

Venation

Parallel

Leaf margin

Entire

Leaf shape

Linear

Growth form

Tree / Shrub

Evergreen/Deciduous

Evergreen

Compound type

Pinnate

Stipules

Absent

Petal fusion

No petals

Ovary position

Superior

Plant sex

Dioecious

Phylogenetic Position

Gymnosperms > Cycadopsida > Cycadales > Cycadaceae

Divergence Era

Paleozoic Permian to Mesozoic Triassic (approx. 280 million years ago onward)

Representative Genera

ソテツ属(Cycas)

Related Evolution Events

  • A 'living fossil' lineage that survived the end-Paleozoic mass extinction
  • Acquisition of coralloid roots with symbiotic cyanobacteria
View on evolution timeline →

Plants in Cycad family on this site

🌿 View in taxonomy
📚ソテツ科の図鑑を探す

AI-generated, needs verification