Gymnosperms
Gymnosperms are the group of vascular plants with exposed seeds. Their name comes from the Greek words gymnos (naked) and sperma (seed). They are believed to have evolved about 400 million years ago. There are 600 known species of gymnosperms alive today. They are most closely related to the group of plants called angiosperms, which have fruit surrounding their seeds to protect them.
One of the reasons why gymnosperms are significant is that they were the first plants to have seeds and pollen. This gave them the ability to grow in very dry regions and survive certain climate differences. The seeds are able to lie dormant for a period of time until conditions are favorable for fertilization. Gymnosperms have two different generations that alternate with one another in the reproductive cycle. The sporophyte generation is the one that's most visible, as it includes trees, bushes, and some vines. The gametophyte generation includes pollen grains and spores, which combine for fertilization.
The species of gymnosperms have a wide range of diversity. The categories or phyla of this group of plants are conifers, gnetophytes, cycads, and Gingko. Of these four, people tend to be most familiar with conifers. They are more commonly known as evergreen or pine trees. The name “conifer" comes from the fact that they produce cones.
There is only a single plant in the Gingko category, Gingko biloba. Extracts from its leaves are used to try to improve concentration and memory, and the tree is also considered decorative. After being around for 80 million years, it no longer grows in the wild.
Cycads are trees that have large cones and palm leaves. Many of them are on the verge of extinction, partially because their habitats are disappearing. Cycads mostly live in tropical climates.
Gnetophytes are an odd and diverse group of plants, and scientists are still debating exactly how to classify them.
General Resources
Gymnosperms – an introduction
New York Botanical Gardens Gymnosperm Page
Evolutiona and Life Cycle of Seed-Bearing Vascular Plants
Overview of Gymnosperms and Angiosperms
Gymnosperms and the Development of Seeds
Photos and Specific Species
Tons of Photos Search by criteria like state or country
Digital Image Library – Gymnosperms
Descriptions and photos of many different species
Greenhouse Photos
Gymnosperm Image Gallery
Resources for Kids
Gymnosperms – First Plants with Seeds
Kids Garden News – Prehistoric Plants
Seed Plants on BrainPop
Conifers – Science for Kids!
For Teachers
Seed Plants: Gymnosperms Grades 6-8
Lesson Plans for Teachers
Worksheets for Science Teachers
Cone Bearing Vascular Plants Lesson Plan Grades 9-12
What Are Gymnosperms? Grades 6-12
