W52 



' ; (2 leaves) 



WATERHEMLOCKS 



Cicu'ta spp. 



Waterhemlocks are, without doubt, the most virulently poisonous flowering 

 plants native to the United States; in fact, they are, perhaps, the most toxic 

 of all higher plants growing in temperate regions of the world, dealing death 

 among both human beings (especially children) and livestock. The several 

 species are known locally as beaverpoison, (spotted) cowbane, musquashroot, 

 poison- or spotted-hemlock, and snakeweed. In the West, they are often, but 

 mistakenly, called parsnips, poisonparsnips, or wildparsnips. The common 

 name, waterhemlock, originates from the wet sites of these plants and, simul- 

 taneously, distinguishes this group from the notorious, closely related poison- 

 hemlock (Co'nium), also belonging to the large carrot, or parsnip family (Um- 

 belliferae). The suffix "hemlock" refers to the deadly, Old World, poison- 

 hemlock, or "hemlock" (Coni-um maeulatum) now, unfortunately, naturalized 

 in parts of our western range country. It is noteworthy, in this connection, 

 that, historically, Conium maeulatum is the true hemlock, a name later usurped 

 by our American tree genus Tsuga. Konrad Gesner, a herbalist of the 16th 

 century, was probably the first to distinguish between Conium and the related, 

 toxic, Old World waterhemlock (Cicuta, virosa), which he called Cicuta 

 aquatica. 1 



Cicuta is a small, chiefly North American genus of about eleven species ; 

 C. virosa is the only one native to Europe and Asia. The waterhemlocks, 

 widely distributed on this continent from New Brunswick and Nova Scotia to 

 Alaska, California, and Florida, and south into Mexico, occur along streams, 

 in swamps, ditches, wet meadows, and boggy places, and in fresh, brackish, or 

 saline marshes in probably every State of the Union. Conservatively speaking, 

 six or possibly seven valid species are found in the West, although many more 

 have been described. The western waterhemlocks usually occur almost from 

 sea level to medium elevations, though occasionally observed at altitudes 

 above 9,000 feet in Colorado and New Mexico. 



It is quite possible that the species of waterhemlock are equally toxic. How- 

 ever, experimental data and other evidence of poisonings and their symptoms 

 are largely concerned with the European species and with four American mem- 

 bers: California waterhemlock (C. calif or' nica), spotted waterhemlock (C. ma- 

 cula' ta), western waterhemlock (C. occidenta'lis) , and tuber waterhemlock 

 (C. va'gans).* Most fatalities reported, both for human beings and animals, 

 are directly attributable to eating the roots, admittedly the most toxic parts. 

 All American species coincide in having some part or parts of the underground 

 portion elongated and decidedly thickened or tuberous ; clusters of fleshy roots 

 are characteristic of many of the waterhemlocks. Unfortunately, however, 

 these underground parts are sometimes mistaken for those of edible plants. 

 The young shoots are also generally recognized as very toxic. The basal part 

 of the leaves of young plants is more virulent than the green blade, and, without 

 doubt, the leaves of older plants are less poisonous than those of earlier 

 growth. 2 Whether the toxicity of the aerial parts decreases with advancing 

 maturity is a matter of dispute. 12 



Most livestock losses and deaths of human beings, due to these plants, occur 

 in the spring. The young shoots are then eagerly devoured, providing tasty, 

 succulent herbage when good forage is unavailable; at that time, greater like- 

 lihood also exists of the roots being pulled up easily from the loose, wet soil 

 where they grow. These underground parts, though evidently very toxic at 

 all times, appear to be particularly dangerous in the spring and in the fall, 

 the greater stored food concentration at those periods seemingly being accom- 

 panied by an increase in the poisonous principle. 



1 Marsh, C. D., Clawson, A. B., and Marsh, H. CICUTA, OR WATER HEMLOCK. U. S. 

 Dept. Agr. Bull. 69, 27 pp., illus. 1914. 



2 Chesnut, V. K., and Wilcox, B. V. THE STOCK-POISONING PLANTS OP MONTANA : 

 A PRELIMINARY REPORT. U. S. Dept. Agr., Div. Bot. Bull. 26, 150 pp., illus. 1901. 



8 Pammel, L. H. A MANUAL OP POISONOUS PLANTS CHIEFLY OF EASTERN NORTH 



AMERICA, WITH BRIEF NOTES ON ECONOMIC AND MEDICINAL PLANTS ... 2 ptS., illU-S. 



Cedar Rapids, Iowa. 1910-11. 



