CHAPTER I 
INTRODUCTION. 
What is a Poisonous Plant? As will be shown later, so-called 
"poisonous" plants differ widely in "degree of harmfulness," and it is 
highly probable that under ordinary conditions many of the plants 
commonly reputed to be poisonous are really almost or quite harmless. 
It is possible, however, that a plant usually unsuspected may on 
occasion prove noxious for example, Nepeta Glechoma (p. 96), in- 
cluded as suspected of poisoning horses. For these reasons, no line of 
demarcation can be drawn to separate actually poisonous plants from 
those which are suspected or are almost certainly quite harmless ; and 
a large number of species is included in Chapter vn as suspected, many 
of them, however, being almost certainly more or less poisonous in 
certain circumstances. In many cases it is practically impossible to come 
to any conclusion as to the degree of toxicity of a plant, owing to the 
want of exact information. Many plants are quite harmless except 
when affected by fungi, moulds, etc. 
A really poisonous plant may be denned as one a small quantity 
of which when eaten induces some form of indisposition with irritant, 
narcotic, or nervous symptoms, with serious or even fatal consequences 
either immediately or by reason of cumulative action of the toxic 
property. 
Harm done by Poisonous Plants. A perusal of the following 
pages will afford convincing proof that the question of the general 
" wholesomeness " of wild plants is worthy of serious consideration 
by all who are interested in the practice of agriculture. Still more 
important is a satisfactory knowledge of the extent to which plants 
are actually poisonous that is, sufficiently injurious when eaten in 
small or large quantities to induce more or less severe indisposition, 
illness or death, with the consequent losses which such bring in their 
train loss of milk and meat production in the case of cattle, of meat 
and wool production in sheep, of power in the horse, of expenditure 
in attendance and veterinary treatment generally, and possibly total 
loss by death of the animals concerned. 
L. 1 
