Image taken from Wayside and Woodland Trees by Edward Step F.L.S (first published 1940, revised and reprinted 1957).
I came across the Wayfaring tree when I was doing some research on the Elder Tree; at first I thought they were the same tree as I hadn't encountered the Wayfaring tree in any of my more modern tree books. The author of Wayside and Woodland Trees says that this name is comparatively recent and the original name for this tree is lost in the mists of time. He quotes John Gerarde, whose 'Herbal' was published in 1597, noting its fondness for for roadside hedges and thickets called it Wayfaring tree or Wayfaringman's tree.William Howitt (1792 - 1879) wrote the following lines:
Wayfaring Tree, what ancient claim
Hast thou to that right pleasant name?
Was it that some faint pilgrim came
Unhopedly to thee
In the brown desert's weary way
'Mid toil and thirst's consuming sway,
And there, as 'neath thy shade he lay,
Bless'd the Wayfaring Tree.
A rather quaint little poem, it captures the idea that the tree gave shelter from sun and rain the the weary traveller of days gone by.
The leaves and kernels have been used beneficially by herbalists and the foliage apparently used to dye hair black.