Why is the common name for Linaria toadflax?
There are several different explanations, not all equally credible. A Dictionary of English Plant-Names by James Britten and Robert Holland (Kartuz Reprint Ltd., 1965) cites the theory of 17th century naturalist William Coles that the name came about “because toads will sometimes shelter themselves amongst the branches of it.” The authors themselves seem doubtful, since they remark on this theory with an exclamation point!
Geoffrey Grigson, in his book A Dictionary of English Plant Names (Allen Lane, 1974) cites naturalist William Turner’s 1548 The Names of Herbes, which says toadflax a translation from the German Krottenflachs, “i.e., a wild, useless flax, a flax for toads.” This too seems a bit of a stretch. What do toads and uselessness have in common?
Elsevier’s Dictionary of Plant Lore, by Donald C. Watts (2007), cites a number of theories. John Gerard, writing in the 16th century, described Linaria as “a kind of Antyrrhinum [Antirrhinum, the snapdragon],” [having small, slender, blackish stalks ]”from which do grow many long narrow leaves like flax. The flowers be yellow with a spurre hanging at the same like unto a Larkesspurre, having a mouth like unto a frog’s mouth, even such as it is to be seene in the common Snapdragon.” Watts doesn’t fully embrace this because it would then rightly be called toad’s mouth. Another thought is that “toad” sounds like the German word tot, for dead. A dead flax could be one that is unusable as a source of fiber, but Linaria also has a reputation as a noxious weed in flax fields.