Branched horsetail
Equisetum ramosissimum
Family · Equisetaceae · Irritating
The plant that looks like a jointed little pine and has neither flower nor seed: it reproduces by spores, like ferns. The genus has existed for over three hundred million years and once made forests of trees.
Streams and ditches · Roadsides and waste ground · Fields and pasture · Town and roadside
Also known ashorsetail, scouring rush
How to tell it
Green, hollow, clearly jointed stems that pull apart at the nodes like fitted pieces. At each node, a sheath of dark teeth around the stem, and fine branches in a whorl. Run a hand over it and it feels rough, like fine sandpaper.
What it is confused with
No dangerous lookalikes known in the Iberian Peninsula.
What it is for
It is so rich in silica that it served to scrub pots and polish wood and pewter, a use that named it in several languages. It had a long tradition as a diuretic infusion. A note that stays on the sheet: it contains thiaminase, which destroys vitamin B1, and sustained consumption has poisoned horses and people.
With documented traditional uses. Not a therapeutic indication and not a dose.