lo Nov., 19 lo.] Reputed Poison Plants. 733 



REPUTED rOISON PLANTS. 



4. C. H. Rothera, J/. .4., M.R.C.S.. Lecturer on Bio-cliemistry in the 



Melbourne University. 



A good deal of uncertainty still exists as tO' the harmlessness or other- 

 wise of many of the nati\e plants of Australia when eaten by stock. So 

 much work still remains to be done, that often the inquiries of stock- 

 owners as to whether a given plant or shrub is poisonous or not cannot be 

 answered with any certainty. As pointed out by Professor Ewart, ill 

 the Weeds and Poison Plants of Victoria, there is no doubt that many of 

 the plants which from time to time come under suspicion are really harm- 

 less enough, and usually, when a plant is (lefinitely poisonous, it very 

 clearly proclaims itself as such. 



Of those plants which are on the border region of doubt, most of them 

 will, in all probability, then be non-poisonous, and a consistent examina- 

 tion of them all would be meeting with a great measure of success if it 

 could prove one specimen in e\ery 20 or so to have poisonous characters. 

 It is the possibility that there may be here and there amongst the large 

 list of plants under suspicion, one or two which are definitely poisonous, 

 that makes a general examination of them all so necessary. 



It is important, in the first place, to say a word or two on what is a 

 poisonous plant, because a plant may be useless, objectionable, or harmful, 

 without being definitely poisonous. A trulv poisonous plant is one which 

 causes symptoms of poisoning, even though it is only eaten in conjunction 

 with other foodstuffs. It will, as a rule, yield definite, active principles, 

 which may be more or less isolated from the plant, and which, when 

 injected directly into the lilood, will cause immediate symptoms and, in 

 large doses, death. 



A harmful plant \vould be one which, when eaten in quantity, caused 

 scouring or other derangement, without leading to any serious poisoning or 

 death. 



Plants are often objectionable to animals owing to bitter principles, or 

 essential oils, though these plants, even if eaten in quantity, are not 

 actually poisonous. The plant is protecting itself from being eaten by 

 stock by means of an unpleasant principle, but not necessarily a poisonous 

 one, at le:ist in the (juantitv likely to be taken at any time by the animal. 



A useless plant' is simply one whose fodder value is so inferior as to 

 make it unattractive and valueless. 



When a plant is distinctly poisonous, it presents very little difficulty to 

 the investigator, compared with the plant which is doul)tfully so. 



It is not fair to continuously feed animals on a given plant, and then 

 call it poisonous if they finally die. If it is to be tested over a long 

 length of time, it must be fed with other foodstuffs, otherwise the results 

 obtained would be misleading, and a plant might be unjustly condemned 

 as harmful or poisonous when there was no more rea.son for such a verdict 

 than there would be. for instance, for a judgment condemning pork, be- 

 cause a man fed on it and nothing else for a week became seriously ill. 

 Neither is it fair to separate the principles of a plant, and inject them in 

 concentrated form direct into the blood. For plants contain principles 

 which are poisonous under such. conditions, as, for examples. Saponins and 

 essential oils, which are not poisonous when the animal takes the plant by 

 mouth in the usual manner. 



