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 GUchoma (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 vii as suspected, many 

 of them, however, being almost certaiuly 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 defined 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. 



Hacm 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 iadisposition, 

 illness or death, with the consequent losses which such bring in their 

 train — loss of Tnilk 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. 



