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Article: Gymnosperms
- Article from:
- Plant Sciences
- Author:
CopyrightCOPYRIGHT 2001 The Gale Group Inc. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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Gymnosperms
Gymnosperms are seed plants that do not produce flowers. The term
gymnosperm
means "naked seed." However, usually when the seeds of gymnosperms are immature they are enclosed within and protected by modified leaves or a cone. In flowering plants (or
angiosperms
, which means "vessel seed") the ovary wall or fruit encloses the seeds, whereas in gymnosperms there is no equivalent structure; hence, the interpretation of the seeds as "naked" or not enclosed.
There are four groups of gymnosperms living today
—
Coniferophyta, Cycadophyta, Ginkgophyta, and Gnetophyta
—
but many additional groups are known from the fossil record. Seed plants evolved more than 350 million ...
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