Wednesday, April 25, 2012

Wood horsetails are an ancient plant

Species name: Equisetum sylvaticum

Common name: wood horsetail

Location: Nova Scotia

Wood horsetails are part of a group of plants called the Pterophyta, which include the ferns. These are vascular, spore-bearing plants (they do not produce fruit or seeds), and have been in existence since the Middle Jurassic (approximately 150 million years ago). Horsetail fossils look incredibly similar to horsetails in existence today. Horsetails in general reproduce through the use of rhizomes, which is a form of underground asexual reproduction (very similar in growth and reproduction to bloodroot). Reproduction in this plant can also occur through spore production in the specialized terminal structure called the sporangium. This species of horsetail is native to the Northern Hemisphere, and has the potential to become invasive in the Southern Hemisphere where there aren't similarly reproducing species on the forest floor.

The wood horsetail is indicative of cooler boreal forests with wet or swampy and nutrient-poor soils. This is pretty typical of maritime forests, and so to see wet areas of the forest understory dominated by horsetails is not unusual.

There are many traditional uses of horsetails in general, and a few specific to this species. The wood horsetail was used medicinally as a tea infusion that was consumed to treat kidney problems and bloating. It was also dried and ground and applied to open wounds to stop bleeding, promote healing and prevent infection. I wouldn't recommend using horsetails for either of these purposes since a few species are toxic and some species are difficult to distinguish. In general, some species of horsetails have been used by native North American people to scour pots after cooking, used in Japan as sandpaper, used to make reeds for musical instruments in the United States, as a vegetable in early spring in Japan and Korea, in experimental trials as a diuretic, and in experimental agriculture as a source of silicon which can prevent fungal infections.