Plants through the Ages Trail Guide
Journey through time at the Kent State Stark Plants through the Ages garden. Our garden showcases the incredible diversity and beauty of plants through time. Start in the Paleozoic, about 500 million years ago, and journey through the time of dinosaurs to the present day, dominated by flowering plants. Follow along with this trail guide to the evolution of plants.
Plants: The Base of Our Ecosystems
- Earliest plant relatives, blue-green algae, first appeared about 3.5 billion years ago
- Photosynthesis, the process through which plants and algae make their own food, first evolved in blue-green algae
- Oxygen, a byproduct of photosynthesis, was generated by these algae and resulted in an oxygenated atmosphere
- Photosynthesis occurred only in the oceans for 3 billion years, finally moving to land about 500 million years ago
- Fossil algae and algal mats called stromatolites are well-known as fossils and still exist in the world’s oceans
- 500 million years ago, plants evolved adaptations to allow them to colonize land
This garden highlights these innovations that allowed plants to dominate the landscape until the present day.
The Cenozoic: Flowering Plants and Grasslands
Typical Cenozoic Plants
Orchids are considered to be some of the most advanced flowers.
Buffalo graze on grasslands, which first appeared in the late Cenozoic.
Yucca is well adapted to dry conditions. They store water in their leaves and are fertilized by moths.
Key events in Plant Evolution during the Cenozoic Era:
- Radiation of flowers to nearly all terrestrial habitats
- Co-evolution of pollinators with flowers, like insects and bats
- Grasslands appeared late in the Cenozoic
- Deciduous trees, which lose their leaves in fall, are adapted to conserve water and energy during cold, dry seasons
- Humans domesticated grasses and other plants
The Mesozoic: Conifers and Dinosaurs Rule
Typical Mesozoic Plants
Gingko trees appeared during the Jurassic. They are hardy and resistant to pollution.
Araucaria trees were one of the first conifers and were likely eaten by sauropod dinosaurs.
Dawn redwood trees flourished during the Cretaceous and are common ornamental trees today.
Key Events in Plant Evolution during the Mesozoic Era:
- Plants with cones, called conifers, dominated
- Cones protect seeds and allow for wind pollination. The yellow dust you often see in spring time is conifer pollen!
- Pine nuts are a familiar example of conifer seeds
- Conifer leaves are small and needle-like to protect from drying out
- Cycads, also known as sago palms, and ferns, dominated
- Ferns covered huge expanses, like grass does today
The Paleozoic: Invasion of Land and the First Forests
Typical Paleozoic Plants
Club Moss grew to tree size. Today, it is a small component of mature forests and bogs.
Ferns still dominate many ecosystems. They grew to tree size and produced seeds in the Paleozoic.
Horsetails usually inhabit damp areas. They were tree-like in the Paleozoic but are now small plants.
Key events in Plant Evolution during the Paleozoic Era:
- Invasion of land by plants
- The first land plants lacked roots and leaves!
- Roots evolved to anchor the plant and take up nutrients
- Tubular structures called xylem allowed water transport
- Leaves increased surface area to gather sunlight for photosynthesis
- Wood appeared about 370 million years ago
- Seeds first appeared in the Paleozoic
- Seeds allow for development of the embryonic plant, protected by a hard outer coat and a food source
The Plants through the Ages garden has received extensive support from the following organizations and individuals:
- Dominion Energy Charitable Foundation Environmental Education and Stewardship Program
- Tennessee Wholesale Nursery
- Jason Veil, Secrest Arboretum, Wooster, Ohio
- GEODES Geology Club, Kent State University at Stark
- Groundskeeping Department, Kent State University at Stark
- Thomas Norton-Smith, Kent State University at Stark
- R.A. (Skip) Schweitzer, Mantua, Ohio