From Wikipedia : “Fasciation (pronounced /ˌfæʃiˈeɪʃən/, from the Latin root meaning “band” or “stripe”), also known as cresting, is a relatively rare condition of abnormal growth in vascular plants in which the apical meristem (growing tip), which normally is concentrated around a single point  and produces approximately cylindrical tissue, instead becomes elongated perpendicularly to the direction of growth, thus, producing flattened, ribbon-like, crested, or elaborately contorted tissue”

This deviant martagon lily (Lilium martagon) turned up in my garden in 2014. Martagon lily have one of the best tasting lily bulbs, and is a good edible for the forest garden as they are shade tolerant :)