Foraging for Horsetail (Equisetum arvense) – An Ancient Ally
The History of Horsetail:
Horsetail is a common road and streamside plant which is descended from huge, tree like plants that thrived 400 million years ago during the Paleozoic era. A close relative of the fern, horsetail is a nonflowering plant found throughout parts of Europe, Asia, the Middle East, and North America. The plant is a perennial (returns each year from the same root structure) with hollow stems and shoots that look like asparagus at first.
It also contains spores, which historically gives us the understanding of this plant coming onto the evolutionary scene after its ancestors; the mushrooms, which arespore bearing, and before pollen bearing plants such as pine, which also learned the art of symbiotization with wind. This is long before flowering plants, which developed seeds, likely in association with mammals coming onto the scene. This is a direct example of plants predictive capacity at its best.
Identification of Horsetail:
To properly identify horsetail, look for them in wet riparian and drainage areas along the 
banks of streams, or where water is known to pool up at some phase of the year. One must also understand that all Equisetum species have 2 forms of plants; fertile stems (light colored due to lack of chlorophyll) which appear earlier in the spring and are followed by sterile stems which are green.
The green, “sterile” plant is what we want for harvest which are abundant in the spring. Once properly identified, it is recommended that one take no more than 30 percent of what is found. This also is coupled with a warning that sometimes horsetail likes to live in drainage areas, which is great for finding and identifying, but not so great for the uptake of potential toxins such as heavy metals and PCBs. This is often similar though, to most conventional food in the grocery stores that modern Americans have become so used to buying without thinking.
The green stems of horsetail are diuretic and homeostatic and help to remineralize the body, especially in the case of other wasting conditions or malabsorption, which can be seen by a skilled practitioner in tongue, facial, eye, hair, and nail diagnosis. Medicinally, Horsetail is deeply rich in minerals, high in silica, and the best time to harvest is before the stems drop to a 90 degree angle to the stalk. After that phase, the plant gets very tough and is reported to cause issues in the kidneys.
Once properly identified and harvested from a wholesome area, then dried, and powdered in a coffee grinder, one can consume ½-1 tsp of horsetail powder as a daily tonic by adding a little hot water daily of to strengthen bones, nails, and hair. It has a cumulative effects and differences will be seen over a few weeks to a month.
Horsetail Medicine:
There is some debate whether the chemical constituents (mainly silica) of horsetail are extracted in an alcohol tincture, and to get around this one could make what is known as an acetate tincture – a mixed tincture of alcohol and vinegar, usually 75/25, or 50/50.
One can also easily extract horsetail in apple cider vinegar by chopping finely or powdering the plant, then adding to vinegar, stirring every few days, and straining in 2 weeks to 2 months.
One potential concern with long-term use of horsetail according to Arthur Haines, horsetails contain thiaminase, an enzyme that destroys vitamin B1 in the body and If used for long periods of time, it could lower body stores of this vitamin. This problem can be overcome by consuming more vitamin B1 when using this species and/or decocting for longer periods of time (thiaminase is a heat-sensitive compound).
Another way to get around this is take horsetail for 2-4 weeks on, and then 2-4 weeks off. As a forager and wildcrafter, these are natural cycles as we track the cycles of nature and receive different amounts of medicines each year from our known spots.
Here is a video for a closer look at horsetail:
Dandelion
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