Classification of Gymnosperms by Sporne: Cycadopsida vs Coniferopsida vs Gnetopsida

Gymnosperms are plants with naked ovules and seeds. They have been placed in between Pteridophytes and Angiosperms.

Sporne (1965) divided Gymnosperm into 3 Classes and 9 Orders.

Class: Cycadopsida (4 Orders )
Order- Pteridospermales (F7) (E) Seed fern
Order- Bennettitales (F3) (E)
Order- Pentoxylales (F1)
Order- Cycadales (F2) (E + L)
Living 11 G and 100 Sp
E.g. Cycas

Class: Coniferopsida (4 Orders)
Order- Cordiatales (F3) (E)
Order- Coniferales (F9) (L) Largest Order 3/4th of living genera
Order- Taxales (F1)
Order- Ginkgoales (F2)
Ginkgo biloba: living fossil

Class: Gnetopsida (1 Order)
Order - Gnetales
Family- Ephedraceae
Family- Welwitschiaceae
Family- Gnetaceae
e.g. Gnetum ula

Following videos will help you for better understanding
1. General Classification of plants: Thallophyta, Bryophyta, Pteridophyta, Gymnosperms, & Angiosperms
   • General Classification of plants: Tha...  

2. General Account of Gymnosperms: General characters, Origin, habit, reproduction, smallest & tallest
   • Gymnosperms: General characters, Orig...