What plants are toxic to horses?

The following is a partial list of plants that are toxic to horses: atamasco lily, bitter sneezeweed, black cherry, black locust, black nightshade, bladderpod, bracken fern, buttercup, castor bean, cherry laurel, chinaberry, choke cherry, coffee senna, cocklebur, fetterbush, great laurel, hairy vetch, hemp dogbane, horsenettle, jimsonweed, johnsongrass, lantana, milkweed, mountain laurel, oleander, perilla mint, poison hemlock, poison ivy, poison oak, pokeberry, rattlebox, red buckeye, redroot pigweed, sesbania, scotch broom, sheep laurel, showy crotalaria, sicklepod, spotted water hemlock, St. John’s wort, white snakeroot, yellow jessamine, privet, red maple, black walnut, azaleas, ligustrum, boxwood, yew, rhododendron. Plants toxic to horses can be found at http://www.ansci.cornell.edu/plants/ Poisonous Plants Informational Database.