22 
BULLETIX 1245, U. S. DEPARTMENT OF AGRICULTURE. 
THE PARSLEY FAMILY (UMBELLIFER.E). 
WATER HEMLOCK (SPECIES OF CICUTA). 
The most poisonous of all the plants in the United States is, with- 
out any doubt, the Cicuta, which is most commonly known through- 
out the West as " parsnip," sometimes as " water hemlock." There 
are several species of Cicuta recognized by botanists, but they are 
very closely allied, and for the purpose of stockmen the description 
of one will serve for all. Plates XXII and XXIII show Cicuta 
vagans.^ the species which is common on the Pacific slope, while 
Plate XXV shows the stems and roots of the species growing far- 
ther east (C. metadata). 
Cicuta is an umbelliferous plant growing i n swamps and damp 
valleys and frequently very abundantly along irrigating ditches. A 
large number of umbelliferous plants* occur in these localities, and 
it is difficult for one unacquainted with botany to distinguish Cicuta 
from similar but non- 
poisonous plants. 
Probably the easiest 
way to distinguish the 
plant is by an examina- 
tion of the rootstock. 
The Cicuta grows from 
a rootstock to which 
are attached roots 
which may be small, as 
shown in Plate XXIII, 
or may take the form 
of a group of thick, 
fleshv tubers, as shown 
in Plate XXV. In 
longitudinal section 
this rootstock slio w s 
more or less distinctly 
a number of transverse chambers, as shown in Plates XXIII and 
XXV. By this peculiarity of structure Cicuta can be distinguished 
from most plants growing in places where it is likely to be found. 
Poisoning by Cicuta. 
IS. — A plant of coyotillo (Karioinskia hinnbuUlti- 
ana) at the time of blossoming. 
It has been commonly thought that the tops of Cicuta when found 
in hay caused the loss of stock, but experimental work of the depart- 
ment has shown quite conclusively that the mature tops and seeds 
never occasion losses, although cases of poisoning have resulted from 
eating the young shoots in the spring. The rootstock and roots arc 
violently poisonous and a very small quantity of these is sufficient 
to kill any animal that eats it. Probably all animals are susceptibly 
to the effects of this plant. The losses of domestic animals arc 
mainly of cattle which either obtain the rootstocks that have been 
plowed up along irrigating ditches or find them along watercourses 
in mountain valleys where they have been washed out by the high 
water. 
