Horsetails

Within PEI’s landscape are inconspicuous, often-overlooked plants that are the only living relatives of species that grew here long before dinosaurs walked the Earth: meet Horsetails (Equisetum spp, with Equisetum sylvaticum shown).

About 290 million years ago, the sediments that would eventually become PEI’s sandstone bedrock were being deposited in the centre of the supercontinent Pangea, near the equator. Growing among these sediments were dense forests, including trees called Calamites that reached heights of 20 metres (65 feet) and resembled giant Horsetails.

At this time, Earth’s climate was changing from the hot and swampy Carboniferous Period to the cooler, drier, seasonally-monsoonal Permian. Calamites wasn’t able to adapt to this change and it died out, leaving evidence of its existence preserved as fossils. Horsetails are not direct descendants of Calamites, but they are cousins and the only members of this family tree still around today.

Horsetails are odd-looking plants, with wiry branches and tiny scale-like leaves pressed flat against the main stem where the branches join it. Horsetails are also very rough-textured plants because they bioaccumulate silica (the primary component of sand) in their outer layers. This feature earned them the alternative name of ‘scour-rush’, and the plants were once used to clean cookware and polish wood and metal. Today, Horsetails are still used as very fine sandpaper in some applications, including fine-tuning musical reeds in wind instruments.

Horsetails have separate, softer reproductive shoots that appear for a short time each spring. These, as well as young vegetative shoots, have been used for food but in limited amounts and with caution. Raw Horsetails have an enzyme that destroys thiamine (Vitamin B1) – a concern not only for foragers, but also for horses if these plants appear in pastures or hay. The enzyme, called thiaminase, is destroyed by cooking.

Additionally, Horsetails’ silica can cause issues with the urinary tract and kidneys. These plants also have a diuretic effect, contain small amounts of nicotine, and can interfere with some prescription medications.

Horsetails are ancient plants that link back to the very origin of PEI Untamed!