Note: The application of a word for the toxic plant Conium maculatum to a conifer began in North America in the eighteenth century, there being a nomenclatural gap, as conifers of the genus Tsuga are not native to Europe. The basis for the name is unclear. According to The Century Dictionary (1889), under the entry hemlock-spruce, the tree was "so called from the resemblance of its branches in tenuity and position to the leaves of the common hemlock, Conium maculatum." Wikipedia states (as of 12/7/21) that "the common name hemlock is derived from a perceived similarity in the smell of its crushed foliage to that of the unrelated plant poison hemlock." — The word hemlock, going back to the earliest Old English glossaries, is without congeners in other Germanic languages. It appears to be attested as both a strong masculine and weak feminine noun. In An Analytic Dictionary of English Etymology: An Introduction (University of Minnesota Press, 2008, pp. 105-08), A. Liberman surveys earlier unsatisfying attempts at an etymology and presents his own hypothesis. He sees a connection with Old High German hemera, glossing the toxic plant names veratrum (Veratrum album L.) and elleborus (Helleborus niger L.). As a plant name, this word has long been compared with Old Russian/Russian Church Slavic čemerŭ "a poisonous plant of the genus Veratrum" (with related forms elsewhere in Slavic) and Lithuanian kemeraĩ (plural) "the plant Eupatorium cannabinum." Liberman, following in part O.N. Trubačev, et al., Ètimologičeskij slovarʼ slavjanskix jazykov: praslavjanskij leksičeskij fond (Vypusk 4, pp. 52-53), segments Slavic *čemerŭ into dialectal Indo-European *kem- and a suffix *-er-, and takes *kem- as the formative element behind hym-/hem- in the hemlock word. The second element -lic- he takes as a suffix of plant names comparable with -ling in Old High German skeriling "hemlock" and -lic in Old English cerlic "wild mustard (Brassica kaber), charlock." In regard to the identity of *kem-, Liberman points to a group of Slavic words cited by Trubačev that show extended senses, as Bulgarian čemer "misfortune, poison, the plant Veratrum," Bosnian/Croatian/Serbian čȅmēr "poison, grief, gall," Slovene čemér "poison, pus in a wound, something bitter," Polish dialectal czemier "Veratrum, pain in a horse's stomach," Russian regional čemer "disease, headache, stomach pain sometimes accompanied by diarrhea and vomiting" (Dalʼ), Russian čemeríca "a plant of the genus Veratrum" (replacing Old Russian čemerŭ). Liberman's hypothesis is then that the base *kem- means approximately "poison, sickness, injury," and *kemer- as a plant name is no more than a derivative from this base, with a suffix *-er- of unspecified ancestry. The difficulty here, however, is that Baltic and Germanic only have the plant name, and neither show the profusion of meanings evidenced in Slavic. It would be more economical to regard the plant name as original in Slavic—the oldest form, in East Slavic, has only this meaning—and the other meanings as derivative ("poisonous plant" > "poison" > "sickness, misfortune, etc."). Liberman attempts to find other evidence of *kem- in Germanic (Old High German hamm "infirm," Middle High German hem "rebellious, malicious," hamen, hemmen "to slow down, retard"), though these and others cited look too semantically and phonetically disparate to be credible. In regard to dialectal Indo-European *kemer-, G. Kroonen cites as well Greek kámaros, kámmaros "name of a poisonous plant, perhaps of the genus Aconitum," and suggests that the entire set of words in Germanic, Balto-Slavic, and Greek reflect borrowing of the name of a toxic plant from a non-Indo-European substrate language (see Etymological Dictionary of Proto-Germanic, Brill, 2013, p. 219). Though it is not without question that there is some relation between this etymon and Old English hymblicae, etc, the possibility seems somewhat remote.