Spores!

When you think of an organism that reproduces via spores, the first thing that pops into your head might be fungus. (Or maybe aliens. I don’t know how you people think.) However, a lot of plants – primarily mosses and ferns and their various relatives – also produce spores rather than flowers and seeds. This morning this tiny forest of moss spore capsules caught my eye.

Moss is a type of nonvascular plant, meaning it lacks the xylem and phloem (vascular tissue) that higher plants use to transport water and nutrients through their bodies. Some vascular plants are spore-bearing, too, however:

This is the underside of a fern frond, and the little tan dots you see are sporangia, where the spores are formed. And of course, we have another type of seedless vascular plant growing in our woods:

Club moss, a.k.a. “princess pine,” which is neither a moss nor a pine but a cousin of the ferns known as a lycopod. The cone-like structures at the top, where its spores are produced, are called the strobili (plural of strobilus), a word I learned in my intro botany class in college that I liked so much it’s stuck in my head ever since. (Unlike sporangia, for some reason, which I had to look up.) A month or so ago when they were fresher you could gently tap on the strobili and send drifts of powdery spores out into the air.

There are other types of spore-bearing plants, too, like liverworts and horsetails. Have you noticed any plants spreading their spores around in your area?

A Dinosaur Forest

What’s called a moss, but isn’t a moss?

What looks like a conifer, but isn’t a conifer?

What’s related to ferns, but isn’t a fern?

These small seedless vascular plants (the same general group that includes ferns and horsetails) are Lycopods, or, confusingly, “clubmoss,” even though actual moss is a nonvascular plant and very different. I can only remember seeing them a couple of times in Ohio but here in Wisconsin there are places in the forest where they seem to completely carpet the ground. The novelty of them makes them fascinating to me – that, and the fact that they are the most ancient and primitive group of vascular plants.

This, I’ve decided, is my Festival of the Trees submission for the month. What do these tiny plants have to do with trees? Millions of years ago, before the tall canopy-creating plant niche was taken over by gymno- and angiosperms, dinosaurs walked in forests that were actually comprised of enormous, tree-sized Lycopods. And where do we draw the line between tree and not-tree, anyway – at what point in their evolutionary history did they lose their arboreal status? Get your eyes (and camera lens) down to ground level and imagine a miniature stegosaurus browsing here – or maybe you won’t have to imagine if a robin comes hopping through, since after all taxonomically speaking birds are dinosaurs.

My very own Jurassic Park, right outside my door.