There are two species of Oak extent in the Blessed Isles, the sessile oak (Quercus petraea) and the penducalate oak (Quercus robur). The two cross quite freely but can be identified, and their hybrids classified, by whether their acorns have stalks (the sessile does not, the pendunculate does) or their leaves do (vice versa). A further distinction is that the sessile oak tends to poorer, rockier ground while the pendunculate prefers the richer lowland areas. Consequently, the sessile is also known as the Irish, Welsh and Cornish Oak while the pendunculate is often known as the English Oak. Both can also be considered native to the Otherworld.
Oak trees are treated with reverence across Europe and the Blessed Isles is no exception in the respect it pays what is otherwise the most common woodland tree. It is speculated that this reverence comes from the oak’s affinity with lightening – studies have proven that an oak tree is considerably more likely to be struck than other trees of a similar height – thus becoming associated with god powers in the primitive mind. However, oak trees are also associated with druidic and fairy traditions. In the first part, the Latin word that became “druid” probably has the same root as the Celtic words for oak and the original word is associated with truth. It was one of only three woods used for wand making (the others being apple and yew, thus associating it with Otherworldly knowledge. For the second part of tradition, the oak is associated with fairy magic, along with ash and the thorns.
As with yew trees, many oaks rooted in our reality are also rooted in the Otherworld. However, Ranger reports from Expeditions and local exploration suggests that the proportion of oaks in both realities is roughly the same – which means, as the Otherworld appears to be significantly larger in its geography, that the number of oaks in the Otherworld is significantly larger than in the Blessed Isles. In keeping with their druidic associations, oak spirit forms are generally described as knowledgeable with a tendency to lecturing.