The toots, upon being cut or bruised, exude an oily, yellowish or reddish 

 aromatic fluid. Cicutoxin, a bitter, disagreeable-tasting, amorphous, resinous 

 substance, resides m the stems and leaves, but mainly occurs in the roots; 

 it is violently poisonous, producing most of the symptoms characteristic of 

 waterhemlock-poisoning. This toxic principle has a powerful and direct effect 

 upon the central nervous system and secondarily influences the activity of 

 the heart and respiratory organs. Even a very small piece of root will usually 

 cause death in a short time. Water hemlocks are probably not only toxic to 

 all classes of livestock, but to warm-blooded animals in general. Although 

 apparently no goat fatalities have been reported, evidence is lacking that these 

 animals are immune to the poison. 1 The maximum losses have occurred among 

 cattle and sheep ; mortality of horses and hogs is also common. 



The sequence in symptoms of waterhemlock poisoning is very characteristic 

 and readily recognized. In man they include nausea, dizziness, abdominal 

 pains, weakened pulse, arching of the back (opisthotonos), and other extreme 

 muscular contractions, violent convulsions, and eventual death from exhaustion. 

 In animals the symptoms are uneasiness, frothing at the mouth, severe pain, 

 muscular twitchiugs, a weak, intermittent, and rapid pulse, and dilation of 

 the pupils (eyes). If the dose is fatal, death comes from exhaustion due 

 to severe muscular convulsions. 1 2 Death may occur within 15 minutes after 

 the first symptoms or, where the first symptoms come in less rapid sequence, 

 within 2 or 3 hours. The poison acts so quickly that usually it is impossible 

 to save the animal. The toxic dose for cattle has been roughly estimated by 

 Hedrick (in Pammel") as a piece of root the size of a walnut. There is no 

 known antidote, but in man the use of emetics has been effective. Bruce 4 

 writes that credit for the recovery of an animal treated with opiates, among 

 other substances, to control the convulsions, is probably attributable to the 

 small amount of poison consumed and not to the remedies. 



Prevention is the only effective control. Hand-pulling is often the simplest 

 method if pieces of the root are not left behind ; grubbing or fencing also have 

 their place. All eradicated roots should be carefully burned, as they are 

 deadly even when dry. 5 Plowing or clearing new land may expose the deadly 

 roots along waterways. Reports persist, probably based on fact, that losses 

 have resulted from contamination of springs and small seeps by water- 

 hemlock roots crushed under the hoofs of animals. However, this danger 

 has probably been exaggerated, particularly as the poisonous principle is only 

 slightly soluble in cold water. 1 



Members of the genus Cicuta are rather similar in appearance ; for practical 

 purposes, ability to identify the genus is essential, though it is hardly necessary 

 to distinguish the 'species. Unfortunately, waterhemlocks and other members 

 of the umbellifer family are often confused on the range. Such related plants 

 as angelicas (Anffe'lica spp.), sweetroots (Osmorhi'za spp.), and woollyhead- 

 parsnip (SpJtenoscia'dium capitella'tum) are harmless and good forage; more- 

 over, they also occur in moist sites. The waterhemlocks are chiefly stout, 

 coarse herbs with smooth, simple, or branched stems, occasionally as high as 

 10 feet, having fairly large, compound leaves, which are divided one or more 

 times into usually even- and sharp-toothed leaflets. Tuber waterhemlock has 

 a distinctive growth habit, with straggling, almost reclining, branches arising 

 from the base of the plant ; the other western species are erect. According to 

 the late Dr. E. L. Greene, 6 the entire plant, including the underground parts, 

 dies after flowering. The underground parts, located fairly near the ground 

 level, are so distinctive that keys for specific recognition have been based 

 upon them. Some American species have a short rootcrown, around which 

 are clustered a group of elongated, fleshy-fibrous or tuberlike roots usually with 

 an additional cluster or tuft of slender or thickened accessory roots; others 

 have an enlarged rootstock, bearing fibrous roots on the under side. California 

 waterhemlock has a freely branching rootstock, the branches close-jointed and 

 enlarged at the ends with fibrous roots at the joints. Published statements to 

 the contrary, the presence of cross-partitions in the rootcrown, rootstocks, and 



1 - 3 See footnotes on preceding page. 



* Bruce, E. A. ASTUAOALUS CAMPESTRIS AND OTHER STOCK POISONING PLANTS OP BBIT- 

 ISH COLUMBIA. Canada Dept. Agr. Bull. 88, 44 pp., Illus. 1927. 



5 Lawrence, W. E. THE PRINCIPAL STOCK-POISONING PLANTS OP OREGON. Oreg. Agr. 

 Expt. Sta. Bull. 187, 42 pp., illus. 1922. 



8 Greene, E. L. VEGETATIVE CHARACTERS OF THE SPECIES OP CICUTA. Pittoma 2 : 111. 

 [1889.] 



