One of my favourite poets is Louise Glück, who recently won the Nobel Prize in Literature. This is from her poem “Witchgrass”:
I don’t need your praise to survive. I was here first, before you were here, before you ever planted a garden. And I’ll be here when only the sun and moon are left, and the sea, and the wide field. I will constitute the field. — From "Witchgrass," by Louise Glück
It reminds me of all the plants that are native to North America yet are often unwanted — the vines, shrubs, trees, grasses, and perennials that we call weeds, nuisance plants, or simply “aggressive.” For instance: hedge bindweed, wild four o’clock, grey dogwood, red osier dogwood, quaking and big tooth aspen, eastern white pine, eastern cottonwood, smooth and staghorn sumacs, Canadian hawkweed, gallardia (blanket flower), self-heal, goldenrod, black-eyed Susan, common milkweed, various persicarias, bidens (beggar-ticks), chokecherry, box elder, stinging nettle, giant ragweed, American burnweed, southern crabgrass, red fescue, and of course Glück’s witchgrass.
They don’t need our praise. They will constitute the entire landscape when we’re gone.
So, I come today not to praise — and certainly not to bury — equisetum aka horsetail: E. arvense (field horsetail), E. fluviatile (river horsetail), E. hyemale (tall scouring-rush), E. sylvaticum (wood horsetail), and E. varigatum (variegated horsetail), all growing here in my part of NH and all natives of North America.
No, I come only to remind us of this plant and its incredible staying power. Equisetum has been around in much the same form on this planet for over 300 million years; it can certainly constitute a (damp) field.
Equisetum is an interesting plant. It comes in sterile and reproductive forms, which look different from each other — the sterile ones look like ferns, and the reproductive ones like strange asparagus spears — and emerge at different times. From the U.S. Forest Service description of equisetum: “An herbaceous perennial relative of ferns, common horsetail consists of two types of stems; sterile, non- reproductive and photosynthetic, and reproductive and non- photosynthetic. The latter, 10 to 25 centimeters long [about 4-10 inches in E. arvense; much longer in some other species of equisetum] with brown scale leaves and a 10 to 40 millimeters long spore cone, emerge in spring then wither and give way to the sterile, photosynthetic stems. These persist from summer until the first frost. It spreads from rhizomes which can grow as deep as six feet.”
Equisetum is seen by some as a nuisance (Google search for equisetum eradicate), but attempts to eradicate or control it are likely to fail due to its deeply buried spreading rhizomes and its ancient memory.
I come also to remind us of the venerable clubmoss, many species of which are native to North America. Clubmoss used to be considered genus Lycopodium (named for a resemblance to a wolf’s paw) and are now split into various genera I can never remember. Some of those here in NH include Lycopodium clavatum (common clubmoss or running clubmoss), Lycopodiella inundata (northern bog-clubmoss), Spinulum annotinum (bristly clubmoss or common interrupted-clubmoss), Dendrolycopodium hickeyi (Hickey’s tree-clubmoss), Dendrolycopodium dendroideum (prickly tree-clubmoss), Dendrolycopodium obscurum (flat-branched tree-clubmoss aka princess pine or ground pine), Diphasiastrum complanatum (northern ground-cedar), Diphasiastrum digitatum (southern ground-cedar or fan clubmoss), Diphasiastrum tristachyum (blue ground-cedar), Huperzia lucidula (shining firmoss), Selaginella rupestris (ledge spikemoss), and more! There are also some related plants, quillworts (genus Isoetes), in New Hampshire but they don’t resemble the others much.
Here are a few photos of various clubmoss or ground cedars spreading out and about in my area:
There are about 1,200 species of clubmoss worldwide, and it can take a plant 20 years to reach maturity and produce spores. Still, where they’re content, they spread at will, but because they thrive in woodlands and not lawns or farms, they’re not considered a problem plant generally, though there is a clubmoss Selaginella densa that’s considered a nuisance in the U.S. western rangelands.
Like horsetails, above, clubmoss is considered a “fern ally” (they all three reproduce through spores) and have been around for literally ages, about 410 million years — they’re one of the earliest groups of vascular plants. So though they’re called clubmoss, they’re not actually mosses. True mosses are bryophytes, non-vascular, no stem or means of holding themselves up, and no way to transport water and nutrients internally via phloem and xylem.
Two genera of lycopodiophyte, Sigillaria and Lepidodendron, now extinct, were very tall tree-like plants that dominated the forests of the early Carboniferous period until ferns gained ascendancy: “Some 300-plus million years ago, tree forms of both clubmosses and horsetails along with ferns dominated the great coal swamps of the Carboniferous geological period. Tree forms of tree clubmosses that once reached heights of 100 feet have left an excellent fossil record of the woody tissue of tree forms” (Prince William (VA) Wildflower Society).
One hundred foot tall clubmoss! I’ve read elsewhere that Lepidodendron reached 165 feet, and horsetail could grow to 110 feet high in the days of yore. Just imagine it. (Or look at some of the dreamy conceptions of the Carboniferous forest online.) It’s a little ironic that the clubmoss we see nowadays looks like diminutive trees and collections of them like props for a shoebox diorama. Still, they were here before us (and before dinosaurs) and almost certainly will live on after us.
More on horsetails & clubmoss:
- Clubmosses: An Ancient and Interesting Group of “Fern Allies,” by Marion Lobstein, Prince William (VA) Wildflower Society
- Clubmoss: An Ancient Forest At Chipmunk Height, Adirondack Almanack, Oct. 2014
- Plant Evolution I: Clubmosses, SUNY Cortland
- Clubmoss, Hiker’s Notebook
- Ancient Equisetum, In Defense of Plants, May 2015.
- Evergreen & Everlasting: The Long March of the Lycophytes, by Julia Runcie, University of Vermont EcoBlog, Nov. 2015
- Rhode Island Equisetopsida, Lycopodiopsida, & Isoetopsida: Horsetails, Club-Mosses, Fir-Mosses, Spike-Mosses, and Quillworts, at Among Rhode Island Wildflowers.
Featured image: equisetum colony, Mink Brook Trail, Hanover, NH, Sept. 2018