Classification of Gymnosperms
Sporne (1965) classified gymnosperms into 3 classes, 9 orders and 31 families. The classes include i) Cycadospsida ii) Coniferopsida iii) Gnetopsida.
• Plants are palm-like or fern-like.
• Compound, frond-like pinnate leaves.
• Manoxylic wood.
• Sperms are motile.
• Flower like structures are absent. Strobili are simple.
Example: Cycas, Zamia.
• Tall trees with simple leaves of varied shape.
• Wood is pycnoxylic.
• Cone like strobili are present.
• Motile sperms are absent (except Ginkgo biloba). Example: Pinus.
• Shrubs, trees and lianas.
• Leaves are elliptical or strap-shaped, simple, opposite or whorled.
• Motile sperms are absent.
• Wood contains vessels.
• Strobili is called as inflorescence.
• Flower like structure with perianth is present. Example: Gnetum, Ephedra.