Natives toxic to horses

Hi, I`m working on a design project along an equestrian trail. At a recent community meeting, equestrians indicated that a number of native plants are toxic to horses. Is anyone aware of specific plants, or of sources to help me track them down? Thanks.</p>

I know that species of Lupinus and Astragalus are toxic to livestock, and there is a good book called 'Weeds of the West', which identifies a number of toxic plants, both native and non-native. Hope this helps.</p>

Hi. I am a landscape designer and a horse owner. I designed a landscape a few years ago for a woman who had horses, chickens, goats and dogs, all of which freely roamed the property. She asked that I not use any plants that could possibly be poisonous to them. I had a book on loan at the time for the project. I don`t have it any more but I think it was called Poisonous Plants of California, by T.C. Fuller. Another good source was a little publication by the Univ. of CA Division of Agriculture and Natural Resources. It was publication 21564, entitled 'Toxicity of Ornamental Plants to Domestic Animals and Livestock' by Ralph Phillips, John Karlik and Murray Fowler. It`s about 3 pages long and includes some natives on this lists as well as non-native ornamentals. I could photocopy it and mail it to you. It might even be free from UC Ag Extension. The last page has about 9 sources listed in the bibliography, one of which is the book mentioned above. Here are some natives they UC say can be used freely around animals: Alnus spp. Cercis spp. Cornus spp. Populus spp. Prosopis spp. Quercus spp. Salix spp. Ceanothus spp. Mahonia spp. They specifically warned not to use the following around animals: Gymnocladus dioica Melia azedarach Robinia pseudoacacia Sapium sebiferum Taxus spp. Kalmia latifolia - mountain laurel Leucothoe spp. Nerium oleander Pieris spp. Rhododendron spp. Clematis spp. Hedera spp. Ipomoea spp. Lantana spp. Lycium halmifolium Menispermum canadense Monstera spp. Parthenocissus spp. Philodendron spp. Senecio confusus Solandra spp. Solanum spp. Trachelosermum jasminoides They also list several plants that should be used with caution in the publication. In adition, I have read that Lupines could be a problem - hay with 10% or more lupines in it is toxic to horses. Here are some other plants that I felt comfortable enough to use after my research. However, it was so long ago now I can`t tell you why or why not I felt they were ok. Romneya coulteri - although there was some discussion of the poppy family in general being a problem, this particular plant was not mentioned as a problem Achillea Clarkia species Gilia Layia platygosa Nemophyla menziesii Penstemons Sisyrinchium bellum Salvias Hope that helps! Thanks for being sensitive to us paranoid horse people! </p>