Cycads

Definition

Cycads are a group of ancient seed plants characterized by their large, compound leaves and stout trunks. They are gymnosperms, meaning their seeds are not enclosed in fruit but rather exposed on cones or similar structures.

5 Must Know Facts For Your Next Test

1. Cycads have been around since the time of dinosaurs, often referred to as living fossils.
2. They possess a unique reproductive strategy involving cones and specialized pollinators such as beetles.
3. Despite their palm-like appearance, cycads are more closely related to other gymnosperms like conifers.
4. Cycads can fix nitrogen due to symbiotic relationships with cyanobacteria found in specialized roots called coralloid roots.
5. Many cycad species are endangered due to habitat destruction and over-collection.

Review Questions

• What distinguishes cycads from other gymnosperms in terms of appearance?
• Why are cycads considered living fossils?
• How do cycads contribute to nitrogen fixation?

Related terms

Gymnosperms:

Seed-producing plants that do not form flowers or fruits, including conifers and ginkgo.

Conifers:

A type of gymnosperm known for bearing cones and needle-like leaves, such as pines and firs.

Coralloid Roots: Specialized roots found in cycads that contain symbiotic cyanobacteria for nitrogen fixation.