Wells Shoemaker 3-21-24
Somewhere around 250 million years ago, horsetails appeared in the fossil record. For a while (100 million years is a long while even in geologic time), these plants comprised a sizeable proportion of the forest floor in temperate climates. Some grew to the heights of contemporary trees!
Almost all of those ancients are gone. Only the lonely Equisetum (Latin for horse tail) genus remains. They’re distributed around the world, but they seem to be particularly happy in the Forest of Nisene Marks. Our Park proudly hosts two contemporary survivors. The Great Horsetail (telmateia, pictured above and below) is rather easy to find in moist areas.
The more reclusive Rough Horsetail (hyemale) seems happiest in lonely places, like the marshy (and currently closed for damage repair) extension of the Bridge Creek Trail to Maple Falls.
Rough horsetail, also known as scouring rush, has abrasive mineral concentrations on the strems and at the joints.
Horsetails grow in characteristic, hollow stalks, with joints called nodes. Slender leaves emerge from the entire circumference of the nodes, resembling a bristle brush. As the plant grows, the sections between the nodes gradually grow longer until the plant reaches a finished height of 3 feet or a little more.
This plant feels “scratchy!” Silicates are concentrated on the surface of the stems and leaves. The rough horsetail has been used historically to scour utensils and render wooden surfaces silky smooth. Call it Green Sandpaper!
Horsetails love moisture, and the last two winters have been banner years for them...and so many other green residents of the Park! Observant hikers will find horsetails growing on riparian benches or near springs and seeps. Concentrations of horsetails on a hillside may indicate areas of shallow water table.
The tips of horsetail leaves act as precipitation points for moisture on foggy mornings, much like the redwood needles above. It seems both of these ancient plants have a knack of extracting moisture from the air!
Horsetails don’t make flowers or seeds. Their rhizomes spread underground with runners, and they stubbornly recover from both fire and floods. They also produce spores on specialized stalks with cone-shaped heads called strobili. The strobili emerge from the soil with a distinctive, snake like appearance, practically slithering upwards before one’s eyes, leading to one common name, “snake grass.”
Horsetails have lasted 250 million years, so they obviously have adapted to adversity long before humans showed up. Once established, they’re nearly impossible to eradicate. If a homeowner has the audacity to pave a driveway over a bed of horsetails...an intrepid horsetail will find a way to puncture the tarmac or pierce the concrete joints...sometimes dozens of them at once.
This determined horsetail sent runners underneath the concrete berm and blasted right up through the asphalt.
Visitors to the Forest of Nisene Marks in the active rainy season can be treated to the
ephemeral Horsetail Falls, easily spotted flowing into Aptos Creek just downstream from
the Steel Bridge at George’s Picnic area. A short stroll down the trail will afford a
splendid “full frontal” view.
Horsetail Falls, also called Christmas Tree Falls, bracketed by a cascade of maidenhair, five
finger, and lady ferns.
Visitors to the Forest of Nisene Marks in the active rainy season can be treated to the ephemeral Horsetail Falls, easily spotted flowing into Aptos Creek just downstream from the Steel Bridge at George’s Picnic area. A short stroll down the trail will afford a splendid “full frontal” view.
A mischievous person could find a small irony here. The generous Marks family grant
that established the Forest of Nisene Marks as a State Park specified that no horses
would be allowed in the deeper portions of the Park (beyond the second gate). That
was a relatively modern regulation. The horsetails, on the other hand, possibly more
primitive in presumption, pretty much go anywhere they want.
Wells Shoemaker MD, March, 2024
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