CH. vn] Plants suspected of being Poisonoiis 93 



though it may possibly be taken occasionally on roadsides. It has not 

 been proved to be poisonous, but Pott states that it has a strongly 

 constipating effect (213). 



Tormentil (Potentilla Tormentilla L.). In relation to supposed 

 bracken poisoning (see p. 87) in regard to which experiments were 

 conducted by the Board of Agriculture and Fisheries, Tormentil occurred 

 in several instances with the bracken in locahties where this plant was 

 reported to cause poisoning. Two feeding experiments in which the 

 weed was fed to heifers gave negative results. In a further case, however, 

 4 or 5 lb. were collected from a field where sick animals were grazing, and 

 fed to a heifer; it appeared to be the cause of rise of temperature (to 

 106° F.), diarrhoea, and the passing of a considerable quantity of blood 

 in the faeces for three days, after which the animal improved. It was, 

 however, slaughtered, and lesions were found similar to those found in 

 animals dying in the field from so-called bracken poisoning. Though 

 the plant was suspected, results generally were not held to prove that 

 it was the cause of poisoning (25). According to Van Kijn the root of 

 Tormentil contains a considerable quantity of Chinovic acid (C32H480g?). 



Wall-Pepper {Sedum aare L.) is regarded as emetic and purgative, 

 but to lose the harmful properties on drying. 



Sundews {Drosera sp.) are reputed to be poisonous to sheep, but 

 no evidence has been found. 



White-Bot or Marsh Penny-Wort (Hydrocotyle vulgaris L.) is stated 

 to have caused inflammation of the digestive tract, and haematuria; 

 and to contain a toxic substance Yellarin (213). 



Wild Parsnip (Pastinaca sativa L.). This plant has often been sup- 

 posed to be poisonous, but Pammel shows that in Iowa the plant is 

 quite harmless, as it appears to be in Britain. 



Devil's-Bit (Scabiosa succisa L.) is stated by Moir to have caused 

 injury to cattle in one instance (Vet. Record, 1899), causing saHvation, 

 gritting of the teeth, twitching of facial muscles, and shghtly protruded, 

 abraded, swollen and sensitive tongue. An experiment on cattle showed 

 the plant to induce violent inflammation of the mouth and tongue. 



All-Heal (Valeriana officinalis L.) is not hkely to be eaten by stock 

 in sufficient, quantity to cause poisonous symptoms, though it is stated 

 to contain the poisonous Valerianic acid and Oil of Valerian. According 

 to Chevalier (aide Henry) this plant contains an alkaloid not yet fully 

 characterised. 



Canadian Erigeron {Erigeron canadensis L.), sporadic in England, is 

 suspected in America. It contains an oil, chiefly a ttrpene (CioHig). 



