Perennial pea (
Lathyrus latifolius) is a perennial climber that can be toxic to horses. Perennial pea plants produce large showy, pea-like pink clusters of elongated flowers and flattened pod fruits.
Lathyrus spp. are generally very similar to hairy vetch (
Vicia spp.).
Toxic components
All parts of perennial pea contain the enzyme beta-aminoproprionitrile (BAPN), which can cause lathyrism.
Lathyrism is a paralysis syndrome. Signs develop from consumption of large quantities of perennial pea over a long period of time. Once signs develop however, they are irreversible, other then surgery might correct roaring.