Gymnosperms
Gymnosperms
Gymnosperms (pronounced: jim-no-sperms) are a group of seed-producing plants that includes conifers, cycads, Ginkgo, and gnetophytes. The term "gymnosperm" comes from the Greek composite word γυμνόσπερμος (gymnóspērmos), literally meaning "naked seeds". The seeds of these plants are not enclosed in an ovary (unlike angiosperms) but are exposed on the surface of cone scales or other structures.
Etymology
The word "gymnosperm" is derived from the ancient Greek γυμνός (gymnós) meaning "naked" and σπέρμα (spérma) meaning "seed". This refers to the unenclosed condition of their seeds (called ovules in their unfertilized state).
Classification
Gymnosperms are divided into four divisions:
- Coniferophyta (conifers)
- Cycadophyta (cycads)
- Ginkgophyta (ginkgo)
- Gnetophyta (gnetophytes)
Characteristics
Gymnosperms are characterized by their "naked seeds" and the absence of flowers and fruits. They have a vascular system for the transport of water and nutrients, and they typically have a life cycle that involves alternation of generations.
Related Terms
- Angiosperms: The group of seed plants that bear their seeds within an enclosure (in other words, a fruit).
- Cone: The reproductive structure of gymnosperms.
- Ovule: The structure in seed plants that develops into a seed after fertilization.
- Vascular system: The complex conducting tissue, formed of more than one cell type, found in vascular plants.
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