The Wisconsin Gardener

cc Well, through the magic of television we've traveled forward 275 million years. We are at the Mesozoic Garden at the Wisconsin Institutes of Discovery on the UW-Madison campus. I am with Dr Ken Cameron Professor of Botany with UW-Madison. You teach what sounds like a really fun class "Plant Morphology and Evolution." Right up my alley. You also are one of the world renowned experts on the Vanilla Orchid. That sounds like a segment for another day. Sure. But today, we are continuing our conversation about living fossils in the garden or in the greenhouse, in this case. This is the Mesozoic Garden. It's open to the public. Let's continue talking about living fossils. Sure, imagine we've stepped into a time machine and we've been transported backward almost 175 million years ago into the Mesozoic Era. This was an important time in the Earth's history in terms of evolution and climate change. We break the Mesozoic up into three periods. 250 million years ago began the Triassic; we moved through the Jurassic; and ended in a period known as the Cretaceous around 65 million years ago. Major time. Exactly, so I mentioned the Jurassic and you've probably heard that word before. Dinosaurs! The Jurassic is well known as the age of dinosaurs. But I'm a botanist. And for me, the most interesting aspect of the Jurassic wasn't the animals, it was the plants. Where would the animals be without plants? So I'm on your side. Imagine this earth is changing in it's climate. Prior to the Mesozoic period, we were in the Paleozoic. Plants, for example, such as this Selaginella which is commonly called Spikemoss these would have dominated the landscape together with plants like this Horsetail Equisetum. We just saw these as enormous fossils where they were tree sized. Yeah, these formed great coal swamps. They ultimately provided us with our fossil fuels. All that survives with us today are a few relatively small species. These itty bitty guys are all that's left. Exactly. But they're beautiful. They lived through the Mesozoic and persist with us as living fossils today. So, no more trees, just these little guys. They're beautiful, though. Today, I can't grow them outside. These are mostly tropical plants. They are popular with horticulturalists as terrarium plants, oftentimes container plants. A kid or a grown-up being a kid could grow a little dinosaur terrarium? Absolutely. In addition to the lycopods and horsetails the Mesozoic of course, had ferns persisting through it which survive with us today. So they are stubborn. Absolutely. Many of these are really popular as house plants, as well. Sure. For example to my right, are some living Tree Ferns in the genus Cyathea. Even here in Wisconsin I grow these on my patio during the summertime. I bring the plants indoors through winter. Again, the idea of sparking a kid's imagination by growing something from the age of dinosaurs. Except for the horsetails, or Equisetum which is actually an invasive perennial for us outdoors the rest of these are tropical and have to be brought in during the winter. A good example of that are the Cycads. If we were in Florida, of course you could grow these outdoors in your lawn. But here is Wisconsin, these would be houseplants. Again the Jurassic period, the age of dinosaurs in my mind is the age of Cycads. These would have been the food of dinosaurs. This is the genus Zamia. We have a few other genera in the garden as well. I wanted to remind you that Cycads are dioicious plants. So you need a male and a female. Exactly, separate sexes on separate plants. The Zamia that I'm looking at right now is actually a male. The cones being are produced in the center of the plant. In fact, if I look at one of these cones in detail and give it a shake, you can see very clearly that it's producing a lot of pollen. This is a male. Behind me are some female individuals of the genus Cycas the large plants behind us. These are all Cycads then? These are tropics, exactly. These are tough plants. These are survivors. Imagine dinosaur lips trying to wrap themselves around these as food. The plants had to be well protected. They have tough leaves a lot of spines, armors on the stem. I also wanted to show you that the females truly are gymnosperms, meaning naked seeds. They don't produce fruits. Their seeds are borne on the sides of their leaves. They're right out there in the open, then. Hence the name gymosperms. Yeah, and other gymnosperms, of course are the conifers, the great trees. For example, pines would be conifers. But here in the Mesozoic Garden we have featured some southern hemisphere conifers. That would be this one here? This one is known as Podocarpus or the Buddhist pine. You can see that the leaves are rather broad and not necessarily needle shaped. It's not going to grow in our climate in Wisconsin? No, but they are grown as container or house plants. Smaller versions, exactly. The one in the way back looks very familiar. Yeah, that's a popular houseplant. That's the genus Auaucaria. It's sometimes called the Norfolk Island pine or the monkey puzzle tree. I've seen smaller versions of that. Yeah, these are popular around the holidays. They're sometimes used as substitute Christmas trees for people living in apartments, for example. These would have been the dominant floristic elements of the Mesozoic. As the Mesozoic faded we moved into the Cretaceous period. The great flowering plants, the angiosperms would take over and become the dominant vegetation on Earth. That's what we're going to look at next. Those will be hardy and plants we can grow outdoors. But here, I mean, anybody could grow tropical plants from the era of the dinosaurs. Ken, thank you so much. You're welcome.