A tangle of plants like tall, green soda straws stick out of the ground on the same stream bank where yesterday’s wild ginger grows. This is scouring rush horsetail, Equisetum hyemale. It’s a cousin of the more common giant horsetail, which looks like an oversized bottle brush with wiry arms that stick straight out from a slim central stalk. But instead of looking brushlike, scouring-rush horsetail is unbranched; it consists solely of a tall, single, hollow stalk. It can grow up to nearly 7 feet tall, always in a dense cluster, spreading throughout the area by slim black rhizome.
The stems of scouring rush are remarkably tough–if you try to break one off you’ll find it unexpectedly hard to do. Equisetum’s flexible strength is due to silicon dioxide, and native Americans used it to polish wood such as canoes, bone tools, soapstone pipes, arrow shafts, and fingernails, or to make mats and baskets; later, settlers and 49’ers used it to scrub their pots and pans. Kids used it as a whistle, and the strawlike stem was used as a straw, particularly to give medicine to infants and others.
Scouring rush tea had a large number of medicinal uses, including for irregular menses, poison ivy, bleeding, infection, kidney problems, backache, lumbago, gonorrhea, and to treat lice. It’s described by Plants for a Future as “anticancer, anti-inflammatory, antispasmodic, diaphoretic, diuretic, expectorant, febrifuge, haemostatic, hypotensive and styptic…with an appetite-stimulating effect.”
The roots and young spring shoots were sometimes eaten; but large quantities are toxic due to the silica.
Flowers Of Marin 