Gymnosperm

Gymnosperms are seed-bearing, vascular plants. The term gymnosperm comes from the Greek word gumnospermos meaning literally "naked seed". This term is applied because the seeds of these plants are not formed in an enclosed ovulary (pistil with one or more carpels, developing into a fruit as in the angiosperms), but naked on the scales of a cone-like structure.

At one time, the gymnosperms were a class (Class Gymnospermae), first within the seed plants (Division Spermatophyta; 1883~1950), later within the vascular plants (Division Tracheophyta; 1950~1981), and essentially encompassing the conifers and their allies (by which was meant "related species of plants" and including several groups of extinct plants known from fossils). These plants were set off from the other classes of higher plants that recognized the ferns and flowering plants.

In modern classification, the gymnosperms are treated as a paraphyletic group, and include the following four groups now given equal rank as divisions within the Superdivision Spermatophyta:

• Division Pinophyta – Conifers
• Division Ginkgophyta – Ginkgo
• Division Cycadophyta – Cycads
• Division Gnetophyta – Gnetum, Ephedra, Welwitschia