Apple and other fruit trees contain prussic acid glycosides in leaves and seeds but little or none in the fleshy part of the fruits. Toxicity can result from improper or malicious use, but in the case of livestock, the most frequent cause is ingestion of plants that contain cyanogenic glycosides. These include Triglochin maritima (arrow grass), Hoecus lunatus (velvet grass), Sorghum spp (Johnson grass, Sudan grass, common sorghum), Prunus spp (apricot, peach, chokecherry, pincherry, wild black cherry), Sambucus canadensis (elderberry), Pyrus malus (apple), Zea mays (corn), and Linum spp (flax).
