Sycamore maple (Acer pseudoplatanus
) is a large deciduous tree of the Maple family. The seeds and seedlings from this tree produce varying levels of hypoglycin A, which is toxic to horses. If enough of the toxin is ingested by horses, it can cause atypical myopathy (AM)
, previously known as seasonal pasture myopathy (SPM) in North America. The seeds are easily distinguishable from their pair of 'wings', called samaras and sometimes 'helicopters'. They are green at first and then turn a tan color when mature, usually early autumn.
Sycamore maple is native to central, eastern and southern Europe and Asia; however it can be found worldwide due to its use as an ornamental. It produces yellow-green flowers which hang in panicles, in the spring, after foliage emerges. The bark is dark pink-grey and smooth when young, but becomes cracked and develops small plates with age. Twigs are pink-brown and hairless.