Hemlock

The name given to a variety of tall plant that grows thickly on open or disturbed ground (the Bonfire Glade in the Old Forest was an ideal habitat for them, and indeed Frodo and his companions found hemlocks growing thickly there). They were also found in the woods of Doriath during the First Age, and especially in the glade in the Forest of Neldoreth where Beren first came upon Lúthien. In his song of their story, Aragorn tells of 'hemlock-umbels', which are the flowers of the hemlock (or, properly, the tightly packed clusters of many small individual flowers that are a distinctive feature of hemlocks and their relatives).

Hemlocks play a surprisingly important role in the beginnings of Tolkien's legendarium, and particularly the hemlocks described as growing in the grove where Beren first came upon Lúthien. In a letter of 1955, Tolkien wrote that, 'The kernel of the mythology, the matter of Lúthien Tinúviel and Beren, arose from a small woodland glade filled with "hemlocks" (or other white umbellifers) near Roos on the Holderness peninsula...' (The Letters of J.R.R. Tolkien, No. 165, in response to an article in the New York Times of June 1955).

(Roos is a small village near Hull in Yorkshire, close to the Humber Garrison where Tolkien was stationed for a time in 1918. The 'umbellifers' he describes are plants of the hemlock type, distinguished by tall bare stems and a crown of small flowers.)