scouring rush

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Any of several species of horsetail, especially Equisetum hyemale, having rough-ridged stems formerly used for scouring utensils.

from The Century Dictionary.

• noun One of the horsetails, Equisetum hiemale: so called on ac count of its silicious coating, being used domestically and in the arts to polish wood and even metals.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun Any of certain horsetails, especially rough horsetail (Equisetum hyemale), formerly used for scouring and polishing.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun evergreen erect horsetail with rough-edged stems; formerly used for scouring utensils