Some interesting notes about Coll (Hazel):

The hazel is a relatively small tree which rarely grows taller than 30 feet but is usually cut back and coppiced so that the twigs and branches grow straight to be used for

The bark is light brown sometimes with yellowish spots.

The leaves grow on alternate sides of the stalks, jagged at the edges, hairy and as large as four inches across.

Around Imbolc hazel trees sprout furry catkins.

Hazelnuts ground to a powder and made into a drink can soothe sore throats. The husks, shells and red skin that covers hazelnuts can also be ground for tea as medicine for heavy menstruation.

Forked hazel wands are a favorite tool of dowsers.

Hazel nuts in Celtic lore are "kernals of wisdom". Also in Celtic traditions, hazel wands were the symbol of a herald or bearer of knowledge.

It takes nine years for the hazel to bear fruit.