Alders

Alders were deciduous trees that grew in Middle-earth, especially in Eriador, such as those that bordered the Water west of Hobbiton, and by the brooks between Weather Hills and Midgewater Marshes. They also were mentioned in the songs of Tom Bombadil to have grown by the banks of Withywindle.

The elves of Rivendell mentioned alders in their song under the window of Bilbo Baggins: "Lullaby! Lullaby! Alder and Willow!".

Moreover, alders were known to have grown in the First Age in Dorthonion by the lake Aeluin.