Teasel
2 of the 6 encyclopedias on this shelf carry an entry for Teasel. Both are reproduced below, so you can see where they agree and where they differ.
Collier's New Encyclopedia (1921)
in botany, the genus Dipsac- About 150 species are known, naus. tives of the temperate parts of the Old World and of America. This order consists of herbaceous and half-scrubby exogenous plants with opposite or whorled leaves and flowers in heads. The only valuable species of the order, D. fullon um, fuller's teasel is four feet high, the bracts hooked, the flowers oval, pale purple or whitish. It is probably only a variety of D. sylvestris. It grows best in a stiff loam. The crooked awns or chaffs are fixed around the circumference of large broad wheels or cylinders, and woolen cloth is held against them. They raise a nap on it which is afterward cut level. A piece of fine broadcloth requires 1,500 or 2,000 of them to bring out the nap, after which the teasels are broken and useless. Steel substitutes for teasels have been tried, but ineffectually; they are not sufficiently pliant, and tear the fine fibers of the cloth. Also in mechanics and cloth manufacture, any contrivance used as a substitute for teasels in the dressing of woolen cloth.
Aiton's Encyclopedia (1910)
tezl, an herb four or five feet high, not related to burdock, but producing somewhat similar heads. The bracts are armed with recurved prickly points. The most common kind, the fuller's teasel, is used to tease or pull up the nap on woolen cloth. No machinery has yet been devised to take its place. Fuller's teasel commands a regular price and is much cultivated in England, also in New York for sale to the woolen mills.
What Has Changed in the Last Century
Both accounts insist the plant is irreplaceable: Aiton's in 1910 says "no machinery has yet been devised to take its place," and Collier's in 1921 that steel substitutes "tear the fine fibers of the cloth." Metal card wire won that argument within a few decades, and the teasel farms that once supplied New York's woolen mills are gone; only a handful of specialist mills still mount natural heads for raising nap on fine woollens and billiard cloth. The plant's second career is as a weed: escaped from cultivation, teasel is now listed as a noxious or invasive species in a number of US states, spreading along roadsides and old fields. Botanically the names have shifted too — Collier's guess that fuller's teasel is "probably only a variety of D. sylvestris" is close to modern practice, which treats the wild plant as Dipsacus fullonum and the cultivated fuller's teasel as D. sativus.
Written for this edition, 2026.