There are multiple types of dystonia, and numerous diseases and conditions may cause dystonia.
Oak is the most common name for trees listed in the genus Quercus. There are a few species that exhibit a shrub type growth form instead of a tree form.There are both deciduous and evergreen species and some are semi-evergreen.Currently there are approximately 600 different species listed in the Quercus (Oak) genus.The tree name  Oak  is also used for the common names of some species in related genera, especially those listed in the Lithocarpus genus.ome evergreen Oak trees (especially certain American Species) are given a grouping common name called Live Oak. This name applies to different species that have an evergreen growth habit, and does not reflect any taxonomic classification group, as these species are distantly related in some cases.
An oak tree is one of the most common species of trees in the Northern Hemisphere which includes North America. Oak trees come in two major prototypes-red oak trees and white oak trees.