Common Mullein: The Vertical Garden

Posted by on Nov 18, 2012 in adaptations, fall, plant parts, Unmowed Blog | 0 comments

The Schoharie Creek, at the bridge in Burtonsville, NY. So mild-mannered now, a calm little rural river minding its own business. But every now and then this quiet stream goes berserk and floods like crazy, toppling trees and destroying houses. They built this new bridge high for a reason.

Anyway, here’s the old bridge, or at least the remains of it. I’m not sure if it washed away in a flood many years ago, or if it was dismantled when they build the new bridge. But the remnants of the stonework have become a really interesting place to look for plants.

A vertical garden.

The gray-green, soft, floppy leaves sprouting out of the side of the old stone wall are specimens of Common Mullein (Verbascum thapsus, one of my favorite Latin names, that just somehow sounds soft and floppy.)

I never cease to be amazed at the ingenuity of seeds. The impossible cracks and inaccessible crevices in which seeds can germinate.

But usually you can figure out how the seeds got to the place where they ended up. The wind blew them, birds carried them, whatever. But the question is–how did the mullein seeds get way up there?

Now, mullein plants are incredibly prolific seed-makers. One single mullein stalk can produce staggering amounts–an estimated quarter of a million individual seeds.

Wait, it gets better. Each mullein seed can survive dormant in the soil for a century before it sprouts. Perhaps longer.

Good grief, it’s almost frightening. How is the world not carpeted with mullein plants? Why are we not up to our necks in these big floppy leaves? Mulleins are a non-native plant, but they’re not remarkably common. Why not?

Well, mullein seeds aren’t adapted to disperse far, you see. They aren’t carried by the wind, borne high on silky parachutes. They don’t hitchhike on animal fur or stick to your socks. How, then, do mullein seeds disperse? They do it in the simplest possible manner–they, well, just sort of fall off the plant. A study in 1978 by botanists–who actually counted all those little specks of seeds–concluded that 93% of mullein seeds don’t travel more than 5 meters from the parent plant. They hit the ground and stay there.

This strikes me as hilarious. (But then, I’m easily amused.) You read all these accounts in nature magazines of the incredible ways that plants have evolved to disperse their seeds, explosive pods and hooks and parachutes and so forth. But the mulleins just can’t be bothered, it seems. The seeds fall to the ground, clunk, and sit there.

So how did these mullein seeds get into the cracks high above the ground? Were they carried to a den by mice? Blown by a wind strong enough to lift them up there? Or maybe they lurked in the soil behind the rocks for decades, biding their time until there were just the right conditions–the rocks shifting a bit, more sunlight, an increase in moisture–that provided the opportunity for germination. Whenever there’s a change in conditions–a flood, perhaps, that lays bare the soil–a few of those dormant mullein seeds spring to life.

Perhaps they fell from their parent plant in 1912, or even before. Maybe a horse-drawn cart or Model-T Ford drove over the old bridge past a floppy mullein plant, and shook loose seeds which waited in the earth, summer after winter after summer, till this very year.

Mulleins are soft as velvet to the touch. Soft, floppy–and very persistent.

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