The current move away from the extensive use of agricultural chemicals and the employment of more traditional methods of farming, means that the number of different plant species is on the increase. Along with the nutritional benefits that this brings, there is also a risk that many potentially poisonous species of wild plants may return in greater number, together with those which, although not outright poisons in themselves, may be toxic to some degree.  Most horse owners are aware of and can identify plants which are the most common cause of poisoning such as ragwort, yew, laburnum and bracken, however, other dangerous species, such as cowbane or hemlock are not usually referred to except in specialist literature.  This booklet lists over 50 plants which are commonly regarded as being poisonous in their own right. An illustration and profile of each is given, together with its prevalence, poisonous principle and symptoms. Each species is given a danger rating.  This information will be of interest to nutritionists and students as well as horse owners interested in being able to identify toxic plants in grazing.