• Structure: Large cones and palm-like leaves

• History: Thrived during the Mesozoic era; few species remain today

• Reproduction: Dioecious (separate male and female plants)

• Habitat: Mostly found in tropical areas

• Example: Cycas revoluta (Sago palm)

• Species: Consists of a single living species

• Features: High tolerance to air pollution; commonly used as an ornamental tree

• Structure: Resembles a pine tree with woody roots, short shoots, and fan-shaped leaves

• Example: Ginkgo biloba

• Genera: Gnetum, Ephedra, Welwitschia

• Diversity: Species vary greatly in appearance

• Habitat: Some are tropical, while others live in desert environments

• Examples: Welwitschia mirabilis

• Group: Largest phylum among gymnosperms

• Structure: Woody trees and shrubs with needle-like leaves

• Reproduction:

-Male cones: Grow on lower branches

-Female cones: Grow on upper branches (e.g., pine, fir, redwood)

• Monoecious: Male and female cones on the same plant

• Life Cycle: Sporophyte (2n) dominant

• Adaptation: Most are evergreens and can carry out photosynthesis year-round

• Special Feature: Produce resin

• Examples: Abies (fir)